Oswalt Kolle, himself nearly 80, was a crucial figure in the country's sexual revolution, producing sex erudition books and films during the 1960s and 70s.
In his autobiography, which will be launched on Monday, he calls for older people to reclaim sexual confidence and to relax about performance.
“Many older people put themselves under pressure. Many women think only she who is young, has beautiful skin and great breasts can show herself naked.
“Instead of thinking about what they no longer have, they should concentrate on their experience. Most will know exactly where to touch her partner," he said.
“And the men must be persuaded not to see sex as a performance,” Kolle said in an interview with the Stuttgarter Zeitung.
“Sex is the best treatment against age-related depression. And lust does not decline. Statistics show 70 to 80 per cent of old people still want sex. Many simply do not have the confidence to accept help.”
He said potency drugs could often be used, but that they were often portrayed wrongly in the media.
“It annoys me when such treatments are portrayed as if they make people horny. Viagra recreates the ability to have an erection. If you take it and go and wash your car, nothing will happen.”
Society in general does not approve of old people having active sex lives, he said.
“Many young people have problems with their parents and grandparents are sexually active, and openly show their rejection. If it was up to them, granny and granddad would be sitting on a park bench reading poetry and feeding the pigeons.”