Although Bixby acted in nine features in the 1960s and 70s, he never did better than second leads ("Speedway" 1968, starring Elvis Presley) or romantic leads in films spotlighting slapstick comedians ("The Apple Dumpling Gang" 1975). His final film appearance was a cameo in the cult comedy "The Kentucky Fried Movie" (1977).

"The Magician" (1973-74), a sometimes interesting adventure series, was less successful than Bixby's two previous programs (even though Bixby did his own magic), but later in the decade he starred in another hit. On "The Incredible Hulk" (CBS, 1978-82), he played Dr. David Banner, a fugitive scientist who when angered pumps up into a large, green, threatening, yet often helpful monster (Lou Ferrigno)--the result of some nasty but obscure brand of radiation poisoning. He brought a more intense edge to his acting than he had ever been called upon to do before, resisting the pulpier aspects of the admittedly sober comic which had inspired the program.

Bixby did not have a major series success after that, though he hosted several syndicated shows, and co-starred in "Goodnight, Beantown" (1983-84, which he co-executive produced), an honorably adult sitcom duet for himself and Mariette Hartley. He also acted in a number of TV-movies, such as "Congratulations, It's a Boy!" (ABC, 1971), "The Couple Takes a Wife" (ABC, 1972), "Shirts/Skins" (ABC, 1973), "The Invasion of Johnson County" (NBC, 1976), "Sin of Innocence" (CBS, 1986) and "Diagnosis of Murder" (CBS, 1992).

Bixby's private life was at odds with his happy-go-lucky image. His son Christopher died at six in 1981 of a throat infection, and his former wife, actress Brenda Benet, committed suicide the following year. In the early 90s, Bixby attracted considerable media attention and public respect for his battle with prostate and bone cancer, undergoing several experimental treatments. He directed the popular teen sitcom "Blossom" right up until his death, and married for the third time on October 3, 1993, two months before he died.