At the time of his death, Keith was suffering from emphysema and terminal lung cancer. He had been a heavy smoker until 1986, quitting a decade before his diagnoses. He was also mourning the death of his 27-year-old daughter,
Daisy Keith, who had committed suicide 10 weeks earlier. He also had financial problems. All of these were contributing factors to Keith's own suicide on June 24, 1997. His last work appeared after his death: voice-over work in the final episode of
Spider-Man (1994), and an on-screen appearance in
Follow Your Heart (1999). He is interred in Westwood Village Memorial Park, Los Angeles, California.
