This article examines the outcomes of participation in mental health Consumer/Survivor Initiatives (CSIs) and identifies helpful qualities of CSIs through a longitudinal, qualitative study that involved in-depth interviews of people who experienced severe mental health challenges in Ontario, Canada. We used a nonequivalent control group design in which we compared active participants in CSIs ( n = 15) with nonactive participants ( n = 12) at baseline and at 9- and 18-month follow-up intervals. Compared with non-CSI participants, CSI participants reported more stable mental health, enhanced social support, sustained work, stable income, and participation in education and training at 9- and 18-month interviews. The helpful qualities of CSIs that participants reported were (1) safe environments that provide a positive, welcoming place to go; (2) social arenas that provide opportunities to meet and talk with peers; (3) an alternative worldview that provides opportunities for members to participate and contribute; and (4) effective facilitators of community integration that provide opportunities to connect members to the community at large. The findings are discussed in terms of previous research in self-help and consumer-run organizations in mental health. [For Part 2, see EJ958021.]