Background: Changes in the appearance of the skin including actinic degeneration and pigmentary changes have been noted in patients treated with psoralen and UVA (PUVA). Objective: Our purpose was to quantify risk factors for increased extent and progression of actinic degeneration and pigmentary changes in the skin of patients treated with PUVA. Methods: On the basis of standardized dermatologic examination conducted in 1977 and 1998 of patients enrolled in the PUVA Follow Up Study, we assessed the prevalence of and changes in the extent of actinic degeneration and pigmentary abnormalities on the hands and buttocks. Results: From 1977 to 1998, the prevalence of moderate or severe actinic degeneration increased from 15.6% to 60.5% on the hands and from 2.2% to 21.3% on the buttocks. During this same period, the prevelance of pigmentary changes of this degree increased from 15.6% to 58.6% on the hands and 12.6% to 24.7% on the buttocks. Extent of exposure to PUVA was the strongest predictor of an increased extent of clinical actinic degeneration or pigmentary change. Conclusion: Long-term exposure to PUVA is associated with persistent increases in actinic degeneration and pigmentary abnormalities of the skin on both usually sun-exposed and sun-protected sites. (J Am Acad Dermatol 2003;48:61-7.)