Beginning in the early 1980s Volker Diehl represented artists such as Leiko Ikemura, Jaume Plensa, Ray Smith, Rosemarie Trockel and Martin Assig. In 1990 he opened the Volker Diehl Gallery at Niebuhrstrasse in Berlin-Charlottenburg.
In 1996 he played a crucial role in the founding of the Berlin art fair ART FORUM and as its subsequent administrative director.
In 2008 Volker Diehl opened the first international gallery for contemporary art in Moscow named DIEHL + Gallery One and staging artists like Wim Delvoye, Jenny Holzer, Zhang Huan, Jaume Plensa and Olga Chernysheva for the first time in the Russian capital. The Moscow branch closed again at the end of 2009.
In September 2013, a project space was added under the name Diehl Cube in Berlin-Wilmersdorf, in which exhibitions were shown until 2018.
Today, the gallery houses contemporary artists like Martin Assig, Thomas Florschuetz, Olga Chernysheva as well as Minjung Kim, Christian Megert, Simon English, Alexandra Paperno, Carmen Calvo, Grazia Varisco or Sergey Braktov. Since 2017 Diehl Gallery is representing the estate of K. P. Brehmer, Turi Simeti and Hal Busse.
Artists presented at Cosmoscow 2021: Martin Assig, K. P. Brehmer, Olga Chernysheva, Amélie Esterházy.