In a maternity clinic two children from families with completely different social backgrounds are switched at birth. One goes on to live in an upper-middle-class family while the other to a poor family. Twelve years later, the mistake is discovered and the child living with the poor family is taken back by his parents, but keeps in touch with his former family and makes them encounter his new brothers and sisters. A series of satirical and comedic scenes follow.
Due in part to the film's being shown on French television rather often, it has gained a sort of cult following among young French people. The song 'Jésus Reviens' sung at church in the film is instantly recognisable to many French youth as a key example of the film's many satirical digs at the French Catholic bourgeois culture in the era it was filmed.
The 2009 film Neuilly sa mère ! was heavily influenced by Life is a Long Quiet River.
The film received 7 nominations at the César Awards :