Collegium Internationale Neuropsychopharmacologicum (CINP) is an international society which was established to facilitate academic exchange of basic and clinical studies related to psychotropic drugs. The CINP has been devoted to the problems of methodology and to the analysis of the pharmacological and therapeutic results with psychotropic drugs under normal and pathological conditions as well to the medico-social implications of neuropsychopharmacology. The CINP was organized by Prof. Trabucchi (Milan) in collaboration with an international team of neuropsychopharmacologists from 15 countries. The first International CINP Congress was held on September of 1958 in Rome. Thereafter, CINP world congresses were held every two years until 2012. The number of Japanese neuropsycho-pharmacologists who are members has been increasing since the 1970s. The 17th CINP Congress was held in Kyoto in 1990, and the CINP Hiroshima regional meeting was held, combined the annual meeting of the Japanese Society of Neuropsychopharmacology and Korean Society of Psychopharmacology in 2001. The early history of CINP between 1958 and 2000 is briefly described with special reference to the participation of the Japanese Society of Neuropsychopharmacology.