The show, which opened on Wednesday, has been hailed as the 57-year-old American pop artist's biggest ever exhibition.
Pennsylvania-born Koons, whose works regularly fetch astronomic prices at auction, is notorious for a series of sexually explicit paintings, photographs and sculptures entitled "Made in Heaven" in 1990-91 with his then partner, porn-star Cicciolina (Ilona Staller).
The Schirn Kunsthalle, one of the city's two contemporary art galleries, is hosting "Jeff Koons. The Painter", with a total 45 canvasses on display, while the smaller Liebieghaus, a villa in a leafy garden on the south bank of the Main River, is showing 44 works of "Jeff Koons. The Sculptor".
One of the main attractions in the Liebieghaus is a gigantic cream and golden porcelain sculpture of Michael Jackson and his pet chimpanzee Bubbles.
His outsized paintings and sculptures of objects such as inflatable dolphins, balloon bunnies and cartoon figures such as Popeye and the Incredible Hulk have led his work to be dismissed as vapid.
"'Kitsch' is a word of judgement. I don't believe in judgement," he told reporters at a press viewing ahead of the official opening.
"I want to show what it means to be human. I like shiny surfaces, to affirm the viewer: you are here."
The Frankfurter Allgemeine Zeitung newspaper was far from convinced. "His art is madly elaborate and technically perfect and car designers can learn a lot from his obsessive handling of varnish and seemingly fluid steel. His works have an effect merely because you can't overlook them. But 'Must See'? No," it wrote in a review.
By contrast, the city’s other paper, the Frankfurter Rundschau found the sculptures – placed among the Liebieghaus collection of antique Roman and Greek marbles – "magnificent".
"They didn't seem misplaced at all" among the busts and statues of past millennia, it wrote. "Never was it more clear that Koons is a sculptor and not a painter."
Liebieghaus curator, Vinzenz Brinkmann, said that "from a certain point of view, Jeff Koons is the last artist of the antiquity," because he, like the ancient sculptors, "shared an interest in the quest for perfection, for craftsmanship and a love of flamboyant colours."
And like them, too, he combined the divine with sexuality, in contrast to the philosophy of Christianity, Brinkmann said.