Chemical peeling involves the topical application of a wounding agent with the goal of effecting an organized regeneration of the skin. The histological and ultrastructural features of actinic- and age-related damage include structural abnormalities that disrupt normal epidermal and dermal architecture. In the present study, five patients with actinically damaged skin underwent an enhanced medium depth peel using 70% glycolic acid and 35% trichloroacetic acid. Biopsy specimens were taken before the peel, and 3 months after the peel for histological and electron microscopic examination. Clinical resolution of actinic damage corresponded with restoration of epidermal polarity. Characteristic histological and ultrastructural features of the skin after peeling include markedly decreased epidermal intracytoplasmic vacuoles, decreased elastic fibres, increased activated fibroblasts and organized parallel arrays of collagen fibrils. We conclude that electron microscopic studies after a medium depth peel of photodamaged skin reveal more profound changes than those seen histologically.