Integration therapy, an integral part of psychedelic-assisted treatment, usually includes sessions devoted to making meaning of relevant psychedelic experiences after subjective effects have subsided. As the psychedelic renaissance continues, offers for this integration therapy have proliferated. In the present project, semi-structured interviews with 30 integration therapists focused on definitions of integration as well as challenges and concerns that they associated with the practice. A mixed-methods approach revealed 19 themes that coders identified reliably. Prevalent themes included expressing concern about nonresponsive clients, defining integration as a bridge between the psychedelic experience and daily life, and apprehensions about the commercialization of psychedelic psychotherapy. Interviewees viewed integration as a process that begins prior to the administration of substances, never ends, makes sense of the psychoactive experience, creates behavioral change, is personalized, and makes the individual whole. Most participants also discussed issues related to client resistance, unrealistic expectations of psychedelic psychotherapy, problems associated with power differentials, the importance of an integration therapist’s connection to other service providers, and the need for self-care. These data might help the standardization of integration therapy, inform lay impressions of the process, and help generate hypotheses for continued research on this aspect of psychedelic-assisted treatment. These data also suggest that psychedelic integration practitioners would appreciate regular support from a community of like-minded colleagues.