After working as post-doctoral scientific assistant, first at the Max Planck Institute of Psychiatry in Munich, then at the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts, as well as at the Rockefeller University in New York City, he graduated with Habilitation in Neuropathology at the Technical University of Munich in 1971.
In 1977 Kreutzberg received a call to the position of Adjunct Professor for Neuropathology at the medical faculty of the Technical University of Munich.
In 2000 Kreutzberg received emeritus status, nevertheless has continued working there with lectures, honorary appointments and advisory activities.
In 1991 he was founding member, and from 1994 to 2008 chairman, of the Scientific Committee of the "International Foundation for Research in Paraplegia" (IFP) in Zurich.
Using the experimental model provided by the facial motor nucleus following axotomy Kreutzberg and his fellow workers discovered essential parameters of the regeneration program of nerve cells.