The present essay looks for evidence of many points of coincidence between the transpersonal psychotherapy of Stanislav Grof and the theoretical elaborations of Carl Gustav Jung; it could even be said that Grof's theoretical work is a continuation of some aspects of Jung's work. In any case, when one reads Grof's work, the influence that it has received from the work of the Swiss psychiatrist is evident, and Grof himself recognizes the valuable contribution that Jung has made to his own work. In reading Grof's books, it can be recognized that the author constantly resorts to notions and theoretical elaborations on the structure and functioning of the psyche that have been initially addressed by Jung. It will be reviewed how Grof ventures into the exploration of expanded states of consciousness from the notions of Jung's notions of complex psychology.