This text deals comprehensively with the aging processes of the skin. It organizes the disciplines of dermatologic gerontology and geriatrics, and critically examines their current content with an eye to future needs. All aspects of the aging processes in the skin are considered: psychosocial effects, medical and financial im-pacts of skin disease, documented use of the skin as a model sys-tem for gerontologic studies, and general theories of aging. Age-as-sociated changes in normal human skin are defined, and previously published studies on this subject are critically reviewed. For each skin disorder, diagnostic criteria, clinical and histologic features, and therapeutic options are reviewed in light of possible pathogenic mechanisms and their relationship to the aging process.