The film was nominated for the Writers Guild of America screen Award for Best Written American Comedy (Joseph L. Mankiewicz).
People Will Talk describes an episode in the life of Dr. Noah Praetorius (Cary Grant), a physician who teaches in a medical school and founded a clinic dedicated to treating patients humanely and holistically. The plot contains two parallel story lines: a professional-misconduct challenge brought against Praetorius by his more conventional colleague Dr. Rodney Elwell (Hume Cronyn), who dislikes Praetorius's unorthodox but effective methods; and the struggle of a distressed young woman named Deborah Higgins (Jeanne Crain), who falls in love with Praetorius while dealing with an out-of-wedlock pregnancy. The film also highlights Praetorius's close friend and confidant, physics professor Lyonel Barker (Walter Slezak), who plays bass viol in the student/faculty orchestra conducted by Praetorius.
At the start of the film, Elwell has hired a detective to investigate Praetorius. A housemaid (Margaret Hamilton) who once worked for Praetorius reacts visibly when Elwell asks her about Praetorius's mysterious friend Mr. Shunderson, who rarely leaves Praetorius's side and has a deep, intuitive understanding of human and animal nature.
Elwell's detective discovers that Shunderson was once convicted of murder, and Elwell calls for a misconduct hearing against Praetorius. At the hearing, Praetorius explains that he started his career in a small town by opening a butcher shop as a front for his undeclared medical practice, because the people of the town didn't trust doctors. Elwell accuses Praetorius of "quackery", but Praetorius defends himself with the fact that he was a licensed practitioner, describing how he was forced to leave town after his maid discovered his medical degree.
Praetorius refuses to answer questions about Shunderson, but Shunderson explains that he served 15 years in prison for the alleged death of a man who had tried to murder him, then somehow survived being hanged after actually murdering the man, who had gone into hiding during the first trial. When he woke up, he was lying on a table in front of Praetorius, who was at that time a medical student examining what he believed was a cadaver. Praetorius kept Shunderson's survival a secret, and Shunderson became Praetorius's devoted friend. After this story is told, the chairman concludes the hearing in Praetorius's favor, and Elwell walks away alone and discredited.
Meanwhile, Deborah enters Praetorius's life, displaying signs of emotional distress. After she faints during a lecture, Praetorius examines her and informs her that she's pregnant. Upset by this news, "Mrs. Higgins" admits that she's not really married. The unborn child's father is dead, and knowing about her condition would be too much for her own father to bear. In a hallway near Praetorius's office, she shoots herself.
After successfully operating on Deborah, Praetorius tries to calm her by telling her there was a mistake in her pregnancy test, but she has fallen in love with him, and becomes upset at her own embarrassing behavior. She runs away from the clinic, forcing him to find her so he can tell her she really is pregnant.
Praetorius and Shunderson drive out to where Deborah and her father Arthur live, a farm owned by Arthur's brother, John. Deborah and Praetorius hide Deborah's shooting incident from her father, who is a failure in life and lives unhappily as a dependent of his stingy brother. Deborah is his only pride in life, which might become intolerable for him with a baby to take care of and his daughter's reputation ruined.
While showing Praetorius the farm, Deborah admits her love for him. She also wonders why he is visiting and begins to suspect that he is attracted to her. After she seductively interrogates him, they share a passionate kiss. They soon get married, and Arthur comes to live with them. A few weeks later, Deborah suggests to Noah that she may be pregnant, and he admits that she was pregnant all along. She ruefully concludes that he married her out of pity, but he convinces her that he really did fall in love with her.
Elwell had purposefully arranged for Praetorius's misconduct hearing to be scheduled for the same time as the student/faculty orchestra's concert. After the hearing and Praetorius' acquittal, the film ends with Deborah, Shunderson, and Barker in the audience watching Praetorius conduct the orchestra in the finale of Brahms's Academic Festival Overture : Gaudeamus Igitur ! .
According to a review at the Films de France website, the movie has a number of political overtones. The review says the film is a reaction to "Mankiewicz’s own experiences during the communist witch hunts of the late 1940s and early 1950s, whilst he was President of the Directors Guild of America (1950-51).
The film's investigative trial has parallels to the congressional hearings by anti-communist crusaders. And just as some refused to name names in such hearings, Cary Grant's lead character declines to clear his own name by revealing the private business of another person, in this case a convicted murderer.
The review said that although the movie is meant as a cautionary tale about the dangers of witch hunts it deals with many other issues, including the pregnancy of a single woman, the "corrosive effect of unfettered capitalism, the human cost of the Korean war, among others."