The plot of Chori Chori is similar to the Hollywood movie HouseSitter. Khushi (Rani Mukerji) is a careless worker always conning her boss and making excuses to not do her duty. She meets Ranbir Malhotra (Ajay Devgan) and learns that the home he plans to build for his love is now a dream unfulfilled. After being dispelled from her job, she locates the bungalow and moves in, informing everyone that she is Ranbir's fiancée. There she meets Ranbir's family and Pooja (Sonali Bendre), Ranbir's love.
When Ranbir returns, at first he is outraged at Khushi's intrusion in his life but then decides to play along with her to make Pooja jealous and fall in love with him. Khushi and Ranbir end up falling in love. However, Khushi's close encounter with reality and Ranbir's old commitments hold them back for a long time before they finally listen to their hearts.