Klaus Gehlen was born in Monschau-Mützenich (Eifel). After completing a design apprenticeship from 1977 to 1980 in Aachen, he then completed another apprenticeship as a wood sculptor and worked as a sculptor until 1996, before opening his own business as a freelance bronze sculptor.

Gehlen workers with stone, ceramic and wood. He set up his studio in his hometown and even set up a bronze foundry in his studio. This has given him a vast depth of knowledge in the different casting techniques. Gehlen's work has a vast spectrum of styles and a wide range of motifs. His large sculptures are often found in public spaces (for instance the "Besenbinder" in Oberhausen, his "Schmuggler" located on the nearby Mützenich border crossing to Belgium or "Schmelztiegel Europa" in Magdeburg), in addition he creates busts, reliefs and animal figures where he portrays his ideas in a realistic and sometimes heavily abstracted representation. Important areas of work for Gehlen are also garden fountains and sculptures as well as the artistic design of everyday objects.