Audio of the interview, which took place in Cuba, was broadcast late Friday along with photos of the 85-year-old Castro.
Castro seemed upbeat as he responded to rumors that he might be ill or near death saying, "You don't say! Well, they haven't told me anything."
He has not appeared in public since a Communist Party summit in April, when he seemed unsteady and unusually frail. He has all but stopped writing his trademark opinion pieces. The silence had led to a fresh round of speculation from Miami, propagated on exile radio and television stations and through social media sites such as Twitter.
The interview with Venezuelan talk show host Mario Silva was recorded Tuesday in the Cuban capital, Havana. Silva first showed photos of the interview, without audio, Wednesday night on his late-night program "La Hojilla," or "The Razor."
Venezuelan President Hugo Chavez referred to the interview earlier Friday, saying Castro "is more alive than ever and with more will to live than ever."
Silva said as he presented the audio Friday night that because the conversation was informal there was no video. He said the interview proved that Castro hadn't suffered a stroke, as some of the rumors purported.
Photographs of the conversation showed Castro appearing relaxed and animated, sitting in an easy chair and wearing a white jacket and green pants. Castro at times gestured with a pointed finger and the two men shared a meal during their talk.
There were also photos of Castro standing as he said goodbye to Silva.
Castro stepped down temporarily, then permanently, in July 2006, handing power over to his brother Raul. He stayed out of the public eye for four years before bursting back on the scene in 2010. But after a flurry of appearances, the former Cuban leader largely went silent again.
Earlier this year, photographs and video were released of Castro meeting with Chavez and other visiting dignitaries in Cuba.