Ajay (Shiva), an educated youth comes to Chennai from his hometown Theni to take up a job. Anjali (Priya Anand), a photographer from London is also in the city to capture the South Indian culture on camera.
The duo are deceived by Narayanan (Santhanam), a real estate broker, who rents out unoccupied houses without informing the house owners. Ajay and Anjali pay the rental money to Narayanan and end up signing the same house. Unable to find another house to rent, the duo decide to stay together till they find Narayanan. They squabble and argue a lot, but soon Ajay falls in love with Anjali. However, he does not reveal her of his feelings. After taking her on a trip to his hometown, he realises that she does not reciprocate his feelings. Soon, Ajay tracks down Narayanan (in a chance encounter earlier, Ajay pockets Narayanan's address from his wallet) and blames him for the misery in his life, because it was Narayanan's trickery that brought them together and now Ajay cannot live without her love. Narayanan decides to help Ajay and he visits the house under the pretense of being Ajay's friend Billa Senthil. He tries to make Anjali fall for Ajay. Anjali's fiance Deepak (Rahul Ravindran) then gives Anjali a surprise visit, just as when she begins to enjoy Ajay's company. Narayanan continues to try to getting Ajay and Anjali together, with no success.
On the night of Anjali's birthday, Ajay decides that she will never love him, and resorts to drinking after being depressed. Meanwhile, Anjali realises that she loves Ajay, but is angry at his behaviour under the influence of alcohol. The next day, she goes to the wedding of Ajay's colleague as his wife (his colleagues think she is his wife) and looks for him there. Just when they find each other and are about to confess their feelings for one another, due to a misunderstanding, Anjali thinks that Ajay and Narayanan are tricksters and have planned the whole same-house plot. Enraged, she returns to London.
Three months later, as Anjali wins her photography contest, Deepak tells her that Narayanan had told him everything from scratch, and convinces her that she loves Ajay and vice versa. Anjali comes back to their apartment, and looks for Ajay, but does not find him. At the same moment, Ajay opens the door and finds his passport that he was looking for. Anjali meets him at last and is thrilled. She asks him why he did not come to woo her for three months in London. Ajay tells her that he had just received his passport and was planning on leaving to the airport. As the two reconcile, Narayanan enters, with a prospective victim (Udhayanidhi Stalin) to trick, and shows him the house. The film concludes showing the same deceiving trick that brought the couple together.
Priya Anand with Shiva cast as the hero. Santhanam appeared in a crucial segment in the second half. The film's principal photography officially began on 1 February 2013 at ECR, Chennai. The director also started working with an environmentalist Abdul to set up a system on the set to educate everyone on environment friendly projects. The film will be released in Dolby Atmos.
Responding to criticism that the film is a blatant copy of 1955 movie Missamma, Kiruthiga denied them as rumours. Although the film is positively reviewed, it is heavily inspired by 2002 Malayalam film Yathrakarude Sradhakku starring Jayaram and Soundarya.
The film's score and soundtrack is composed by Anirudh Ravichander. The album was released on 27 July 2013 at Suryan FM and reached top spot in iTunes India Top Album category within few days of its release. The album consists of seven songs and he will be teaming up with Vishal Dadlani for Oh Penne song. Also in the album are Singers Arjun, Vishal Dadlani, Hiphop Tamizha, Pragathi Guruprasad from 'Super Singer' & Hard Kaur. Lyrics for "Engadi Porandha" was written by Vignesh Shivan, director of Podaa Podi.
The satellite rights of the film were sold to Sun TV. The film was given a "U" certificate by the Indian Censor Board.
Vanakkam Chennai received positive reviews from critics. S Saraswathi of Rediff said, "Vanakkam Chennai is a fun-filled, but slow paced romantic film that does not boast of a great or original storyline. But there is simplicity and charm in the characters. And the great music certainly keeps you entertained." Prashanth Reddy of Desimartini said, "Anirudh's music is a huge positive and I can't seem to get a few of the background tunes out of my head. Priya Anand looks utterly gorgeous in every frame. But "Vanakkam Chennai" is still just an okay-ish Rom-com that is hard to hate. It is does very little to reinvigorate a stagnant genre. Also, it should have avoided using Santhanam." Baradwaj Rangan of The Hindu called it "A low-key bliss-out for the most part."
Behindwoods said, "The first half trots along merrily with Ajay (Shiva) and Anjali (Priya Anand) indulging in one-upmanship that stirs up several laughs and saves the audience the trouble of wondering about the story's progress. But the second half, despite Santhanam's shenanigans, plays out more like a drama. This in turn stretches the movie to a running time of 2 hours and 31 minutes and much like Rosy Aunty, Vanakkam Chennai too takes its own time to say goodbye." IndiaGlitz said, "Though a rather predictable story, the knack of this success lies in the way it has been wrapped and presented. As you sit through the movie, it is natural for anyone to forget that Kiruthiga is a debutante director for, she has worked this movie to perfection in every frame." Sify said, "The film has nothing new to offer but is still enjoyable due to its glossy packaging, rich visuals and lots of fun. It’s a charming film made with heart. Give it a chance, you won’t be disappointed."