In 1970, he was allowed to produce a television special, The George Kirby Show, to gauge whether he could attract an audience for a weekly series. This led to his hosting a sketch comedy and variety show, Half the George Kirby Comedy Hour, which lasted for 22 episodes in 1972; it was also one of the actor-comedian Steve Martin's first credits in front of the camera. The series was in many ways an uneasy compromise between Kirby's natural gifts and what the public would accept of Black actors at the time; a regular feature was a shaggy dog story segment entitled the "Funky Fable". He was also a regular in the British-produced ABC Comedy Hour series The Kopycats, alongside such other impressionists as Rich Little, Charlie Callas, Marilyn Michaels, and Frank Gorshin.
Following the demise of his show, Kirby's career declined, especially as audiences began to look for more cutting-edge comedy. He had been an occasional drug addict; now, to make up for lost income, he took to selling drugs. In 1977 he sold heroin to an undercover cop; he plea bargained to a ten year prison term and was released after 42 months. His career never again reached its former heights, but he did register featured guest appearances on Gimme a Break with Nell Carter, Crazy Like a Fox, and 227. He then took ill with what was later diagnosed as Parkinson's Disease. He was well-loved enough within the comedy community that friends and admirers formed the "Friends of George Kirby", which performed an all-star tribute to him in 1995 to help pay his mounting medical bills, only a few months before he died.