There is a growing body of literature that describes the theory of and practice with mutual aid groups. Much of the literature is generic in nature in that it describes mutual aid groups in general terms. However, groups of persons experiencing one vulnerable life condition or circumstance will bring different issues and behaviors to mutual aid groups than groups experiencing other conditions or circumstances. Hence, the knowledge base supporting practice with mutual aid groups must be particularized to the different vulnerable populations. This paper attempts to particularize mutual aid theory to group practice with mentally ill older adults. Mutual aid themes that are unique to older persons with a mental illness are explored.