Hans Hoff was director of the department of Neurology and Psychiatry of the Vienna University from 1950 till 1969. That period is often called the golden age of psychopharmacology since at that time psychiatric research with psychedelics became important and all the diverse types of classical antipsychotics and anxiolytics were detected and introduced into treatment. Faculty members in Vienna participated very early in such research initiatives. Hoff, eager to revive pre-war approaches in clinical psychiatry, wanted to construct a Psychiatric system that used biological and psychoanalytical theories and methodologies in a synergistic way. He therefore was very interested to participate at the than new and fashionable research on new psychiatric drugs. Since his First assistant, Ottokar H. Arnold, shared the interest in that issue it was possible, that the Viennese clinic became one of the leading European centres for clinical psychopharmacological research. That research exceeded simple pre-marketing clinical trials. Using Moreau de Tours’ paradigm of pharmacopsychiatry. Hoff and Arnold tried to use drugs as research tools for gaining insight into psychopathological processes. They also developed concepts concerning the effects of the psychiatric drugs and finally produced a critical assessment of the importance of the medications for psychiatric treatment.In 1957 Hoff and Arnold became founding members of the CINP, an international scientific umbrella organisation for all professions concerned with neuropsychopharmacology. From 1962 to 1964 Hoff served as president and Arnold as secretary of that organisation. In the discussions during the meetings of the CINP Hoff always represented the theoretical and practical orientation of the “Viennese school”. That orientation included the firm conviction that mental diseases are not resulting from a single biological disturbance but should be understood as multifactorial diseases, resulting from the interaction of influences from biology, psychology and the environment. At that time, however, such an interpretation was not at all extravagant. Hoff and Arnold shared it with a group of excellent representatives of psychiatry within the CINP. The structure of the Austrian membership within the CINP was somewhat special. While inmost of other member states clinicians and pharmacologists were represented, the Austriangroup consisted of clinicians only. Even important Austrian pharmacologists appeared onlysparsely during conferences and never claimed for membership. This seems peculiar sincewithin the CINP many excellent neuropharmacologists were represented. The background ofthat situation remains to be investigated.