L. B. Jeffries is a talented photo journalist who breaks his leg while on assignment. After weeks of being stuck in his apartment he's taken to spying on his neighbors via his window, where he can see the entire courtyard and the buildings surrounding it. He notices that the salesman across the way is suddenly alone, his wife gone. Jeff suspects that the salesman, Lars Thorwald, has murdered his wife. He enlists the help of his girlfriend Lisa (Grace Kelly), nurse Stella (Thelma Ritter) and detective friend Thomas Doyle (Wendall Corey), to solve the mystery.