Klaas Gubbels experienced the bombing of his hometown Rotterdam at the age of six. On the one hand, his childhood took place between burnt-out and ruinous houses in the city centre, and on the other hand with his grandparents, who lived on Balkengat (now Balkenstraat), near a small harbor of a timber mill on the Delfshavense Schie.

Gubbels came into contact with the visual arts through his father Kees Gubbels (1894-1974), who founded Kunsthandel De Brug during the war. In the fifties, Gubbels followed various courses.

He studied advertising painting from 1949 to 1951 at the Technical School in Rotterdam. He then found work at the advertising studio of the Rotterdam Bijenkorf.

From 1951 to 1952 he followed an evening course at the Rotterdam Academy of Visual Arts. As a result of his parents' divorce, Gubbels left for Arnhem in February 1952, where he studied from 1952 to 1958 at the Academy of Art Practice in Arnhem. He also took evening classes in sculpture. Gubbels did not take his final exam for fear of failing the art history section.

In the 1970s, Klaas Gubbels was a teacher at the Rotterdam Academy of Visual Arts, now Willem de Kooning Academy, together with other painters and graphic artists such as Hannes Postma and sculptor Kees Franse. Gubbels works in Arnhem in his studio in the coach house of the Lichtenbeek estate or in France in the Ardèche.

In 1955 Gubbels had his first exhibition together with Just Sark in the university mensa in Utrecht, and at bookstore De Violier in The Hague, in 1965 his first exhibition abroad, in Lisbon and Paris.

At the end of 2004 and in the beginning of 2005 a large retrospective exhibition of his work took place in the Museum of Modern Art Arnhem. Ten years later, Gubbels' eightieth birthday was celebrated with a special themed exhibition at Soestdijk Palace (September to November 2014).

Gubbels' work is represented in various major Dutch museums and in the corporate collections of, for example, Ahold, Akzo and TNT.

Over time, Klaas Gubbels' artworks have become increasingly abstract. It can be seen as monotonous at first, due to the limited number of visual themes. But this is also the strength and charm of his works of art, according to some. He also uses a multitude of techniques and materials, such as: photography, litho, woodcut, wall painting, collage, objet trouvé, glass and metal.

His work interfaces with artworks by artists such as Giorgio Morandi and Amedeo Modigliani and appears to be influenced by Marcel Duchamp, Man Ray and George Segal.

In 2013, on the occasion of Jan Siebelink's seventy-fifth birthday, a special edition was published with fragments from Kneeling on a bed of violins and ten woodcuts by Gubbels inspired by them. The Singer Prize was awarded to him in 2022.