This paper examines the various meanings persons with serious mental illnesses attribute to the concepts of religion and spirituality. In-depth semi-structured interviews were conducted with forty individuals with serious mental illnesses who have incorporated alternative healing practices into their recovery process. The qualitative data analysis revealed that study participants differentially defined religion and spirituality using two sets of descriptors: (a) core characteristics describing the nature of each concept, and (b) functional characteristics describing the impact of religion and spirituality on the individual. Implications for clinical practice and future research on the role of religion and spirituality in recovery are discussed.