The film has a theme on the rehabilitation of prostitutes which was then a controversial topic. Furthermore, the film also questioned on the society of prostitution.
The story revolves around professor Mohan who lives with his ailing mother and his mother would like him to get married but he oppose for this. Suddenly his mother loses consciousness and is not expected to live long and only way the son has to save her is to get married. So he brings a woman Rajini who is then introduced to his mother. Now His mother's health improves and his mother is so pleased with Rajini that she even gives her the family jewels. Then the mother and son receive the shattering news that the Rajini is actually a prostitute.
Professor Mohan (Sunil Dutt) is a morally upright, honest young man living with his beloved mother (Leela Chitnis), who is singleminded in her pursuit of one goal. Mohan teaches literature and poetry at a nearby college. During one lesson about a nobleman who has fallen for a prostitute, he makes his feelings about dancing girls quite clear. Not long after, his mother, who is running a fever, falls down the stairs in their home and is unconscious. The doctor is called, injections are given, the neighbors all come crowding in, and much shaking of the head ensues, but she finally regains her senses long enough to say this. The doctor pronounces his judgment that with the medication, she will get better; but the packed-in neighbors are much more gloomy. They all file out, still muttering amongst themselves. One of the neighbors, Jeevan (Radhakrishan), has creditors hounding him, and he sees a little opportunity to make some money. He tells Mohan that he knows a girl who might be persuaded to pose as his fiancee for a few days, but her father will probably want money. Mohan of course is willing at this point to do anything and agrees to give Jeevan whatever he wants. Jeevan goes to see Champabai, a local tawaif. He negotiates a price with her for posing as Mohan’s fiancee for the evening. She puts on a demure sari and he takes her to see his mother and meet Mohan. His mother wakes up long enough to bless her before falling back into a deep sleep. Champa for her part is unimpressed by either mother or son and mocks them when she gets home. Jeevan gives her money, which is promptly pocketed by the brothel owner Lallubhai. The next day Mohan's mom asks to see "Rajani" again, and Mohan asks Jeevan to bring her again that evening—Jeevan has told Mohan that she is the daughter of a distant relative. In any case, Champa/Rajani is bowled over by the expensive jewelry that Mohan's mom shows her as the family bride-to-be. She decides to forgo her fee, to Jeevan’s dismay, in favor of pretending to have real feelings for Mohan until she can find an opportunity to steal it. She soon does, as one day Mohan's mom gives her the bridal sari and jewelry to take home and try on. She puts on her finery for her customers that evening, and they make fun of her. She flees in humiliation and the jewels she put on so happily moments before now feel like they are scalding her. Her customers sing a lively qawwali to try and coax her out. But when she emerges, this time in her dance costume, they laugh at her again and she realizes that she means nothing to them, they don’t think of her as a person with feelings or emotions. The next day, subdued, she brings back the jewelry and bridal sari to Ma, who is recovering nicely. Ma’s warm greeting and kind affection makes her feel even worse. Meanwhile, Mohan has fallen for Rajani, and he wants to speak to her father. Jeevan puts him off, and he returns home to find Rajani there. He expresses his affection gently, and she tells him that she is not worthy. She leaves sadly, and the next evening refuses to dance for her customers. Lallu’s threats don’t move her either, and she throws him out after an impassioned speech about how he has been living off her earnings for years. He goes, but vows that he will make her dance in the bazaar. She goes to see Jeevan and makes him promise that he won’t tell Mohan the truth about her, not because she thinks she has a future with him, but because she can’t bear to become a lesser woman in his eyes. Soon after that, Mohan sees Rajani walking in the street. When he calls her name she flees, and he follows her to her house. Mohan is horrified and angry. He tells his bewildered mother that he will never see Rajani again.Vyjayanthimala as Champabai / Rajani
Sunil Dutt as Professor Mohan
Leela Chitnis as Mohan's mother
Radhakrishan as Jeevan Ram
Manmohan Krishna as Lallubhai
Uma Dutt as Pahelwan
Ravikant as Doctor
Sant Singh as the Art director
R.G. Gaekwad as the assistant art director
Jaywant S. Worlikar as the Audiographer
S. N. Modi as the assistant audiographer
S. N. Sharma as the assistant audiographer
Shanker Ram Jadhav as the Make-up artist
Ram Singh as the assistant make-up artist
Costume and Wardrobe Department
Vasant as the Costume designer
Camera and Electrical Department
Dharam Chopra as the Camera operator
Roshanlal Sharma as the Unit still photographer
Vithal Narayan as the Focus puller
P. R. L. Raman as the Clapper loader
Abba Joshi as the film processing
Krishnan Sachdeva as the assistant editor
Second Unit Director or Assistant Director
O. P. Bedi as the Assistant director
Yash Chopra as the Assistant director
Balbir Kumar as the Assistant director
G. D. Bhadsavle as the Publicist
Jaikishan as the Production assistant
Laxmi Narayan Yadav as the Production assistant
C. L. Kapoor as the Production executive
C. V. K. Sastry as the Production Controller
Mohanlal Harkishenlal Sibal as the Presenter
B. Sohanlal as the Choreographer
Bhadrakumar Yagnik as the Public relations
For the lead role of Champabai, who is a prostitute, the initial consideration for that role was actress Nimmi, but she hesitated to enact a role of a prostitute and reject the offer which was instrumental in her career decline by the late 1950s. Later, actress Vyjayanthimala who previously worked with B.R. Chopra in Naya Daur (1957) agreed to be part of the film immediately after hearing the script from the director. Furthermore, Yash Chopra, the younger brother of B.R. Chopra, was an assistant director during the making of Sadhna. B. R. Chopra later gave him his break as a director the next year with Dhool Ka Phool (1959).
The film's soundtrack was compose by Datta Naik who had a break through this album. Later on he composed some of the best Bollywood songs in the film Dhool Ka Phool (1957) and Aag Aur Daag (1970).
The lyrics were provided by Sahir Ludhianvi and the vocal's were provided by Lata Mangeshkar, Mohammed Rafi, Bhupinder Singh, Geeta Dutt and Asha Bhosle.
Sadhna received largely positive reviews from the critics and was one of the most critically acclaimed film of the year. Vijay Lokapally from The Hindu said, "Among the great movies made on the subject of helpless women versus society, Sadhna holds its own for its realistic portrayal and treatment of a subject, so aesthetically documented by Chopra and Vyjayanthimala". While actress Vyjayanthimala was praised by the reviewer whose performance was described as "gorgeous when she entertains the clients at her kotha" and "stunningly restrained when she assumes the character of a prospective wife". Adding to that, "she slips in and out of the two challenging and contrasting roles with élan, a remarkable feat for an artiste who was only 22 and hardly 10-films old when she signed to play this difficult but decisive role in her dazzling career" and concluded that "the movie is all about Vyjayanthimala’s skills as a dancer and an actor[...]is captivating in her dancing numbers[...]The Filmfare Award for Best Actress that year could not have gone to anyone else even though she was also nominated in the same category for Madhumati."
Similarly, the Rediff's reviewer Dinesh Raheja has commented that, "Sadhna was quite progressive in its approach, boldly dealt with a prostitute's love story with a literature professor[...]it dared to portray not just the often seen tragic trajectory of a prostitute's life and times, but a happy ending as well". Furthermore, Raheja added that, "Though Chopra's narrative style is conventional, he needs to be commended for attempting a reformist tale". The music director Datta Naik and the lyricist Sahir Ludhianvi was praised for their involvement, especially the "Aurat Ne Janam Diya Mardon Ko" was described as "crowning glory" and "hair-raising" song of the film.
At the end of its theatrical run, the film grossed around ₹16,000,000 with nett gross of ₹8,000,000, thus becomes the fifth highest-grossing film of 1958 with verdict hit at box office. According to Ibosnetwork.com, the film had been grossed at about 8,000,000 and its adjust to inflation gross is about ₹ 2,134 million. The film was the third direct box office hit film for the B. R. Films banner after Ek hi Raasta, &Naya Daur (1957 film)|Naya Daur]] (1957) and the sixth consecutive hit of B.R.Chopra as director after Afsana,Shole and Chandni Chowk.. After Sadhna which made Chopra financially the most-viable banner, the top heroes and heroines were prepared to work with him at half their remuneration for the box office guarantee offered by his banner.