Complementary and alternative medicine (CAM) has been gaining interest among individuals with serious mental illnesses. Yet, very little is known about how CAM may be beneficial to mental health. This study explored the specific benefits attributed to CAM by a national sample of 255 individuals with a serious mental illness who experienced CAM as having a positive impact on their mental health. Data about the CAM benefits were gathered through open-ended questions embedded in a mail survey that examined the patterns of CAM use in this population. Qualitative analysis revealed a wide spectrum of benefits that encompassed all major areas of human functioning, including physical, emotional, cognitive, self, social, spiritual, and overall functioning, and addressed both the improvement of psychiatric symptomatology and the promotion of functional recovery. Study findings provide useful information that can guide both everyday clinical practice and future research on the efficacy of CAM for psychiatric populations.