Margraf is considered a leading expert in the field of clinical psychology and psychotherapy. One of his specializations is the treatment of anxiety disorders. He is an advocate of short treatment forms evaluated with regard to their efficacy. In his work, he aims to identify conditions for good mental health in order to prevent illnesses. He was Chairman of the Scientific Advisory Board on Psychotherapy from 1999 to 2005. He has been the President of the German Psychological Society from 2012 until 2016. At RUB, he strengthens the Clinical Psychology research area and heads the Mental Health Research and Treatment Center.