In the 1930s Kapoor worked as a clapper-boy for the Bombay Talkies and as an actor for Prithvi Theatres, two companies that were owned by his father, Prithvi Raj Kapoor. Raj Kapoor's first major screen role was in Aag (1948; “Fire”), which he also produced and directed. In 1950 he formed his own Bombay film studio, RK, and the next year achieved romantic stardom in Awara (1951; “The Vagabond,” or “The Tramp”). He also starred in such successful films as Barsaat (1949; “Rain,” or “The Monsoons”), Shree 420 (1955; “Mister 420”), Jagte Raho (1956; “Stay Awake,” “A Night in the City,” or “Under Cover of Night”), and Mera Naam Joker (1970; “My Name Is Joker”), many of which he also wrote, produced, and directed. Some of the films he directed featured his two brothers and his three sons.

Although Kapoor portrayed romantic leads in his early movies, his best-known characters were modeled on Charlie Chaplin's poor but honest tramp. His use of sexual imagery often challenged traditionally strict Indian film standards. Many of his film songs became musical hits. On May 2, 1988, during an awards ceremony at which he received the Indian film industry's highest honour, Kapoor suffered an acute asthma attack and collapsed; he died one month later.