Phoenix gave an impressively mature performance as a knowing tough kid in Rob Reiner's poignant coming-of-age drama "Stand By Me" (1986). That same year, he played Harrison Ford's eldest son in Peter Weir's "The Mosquito Coast". In 1988, Phoenix played a socially ambitious teen whose plans are seriously altered in "A Night in the Life of Jimmy Reardon" and, opposite Sidney Poitier, the initially unsuspecting son of Soviet agents in "Little Nikita". Although he never acquired the commercial clout of some of his contemporaries, Phoenix became known for his nuanced and heartfelt performances. He received an Oscar nomination for Best Supporting Actor as a piano student on the lam with his fugitive '60s radical parents in Sidney Lumet's "Running on Empty" (1988) and captured the essence of Harrison Ford playing a young Indiana Jones in the riotous prologue of "Indiana Jones and the Last Crusade" (1989). He clearly emerged as the leading actor of his generation in Hollywood with a courageous portrayal of a gay narcoleptic street hustler in Gus Van Sant Jr.'s "My Own Private Idaho" (1991). He also gave impressive performances as a mystic pizza man in Lawrence Kasdan's black comedy, "I Love You to Death" (1990) and a young Vietnam-bound Marine in Nancy Savoca's "Dogfight" (1991).
Also a talented musician, Phoenix formed the rock band Aleka's Attic with his sister Rain. He sang and played guitar in the country-western drama "The Thing Called Love" (1993). Phoenix's final credit was metaphysical Western, "Silent Tongue" (also 1993), written and directed by Sam Shepard. Before his untimely death on Halloween night 1993, he was set to play the interviewer in Neil Jordan's adaptation of the Anne Rice's "Interview with the Vampire". He had also nearly completed work on the independent thriller "Dark Blood", with Judy Davis.