Background: The efficacy and safety of UVA1 (340-400nm) phototherapy were established by studies from European countries. Purpose: Evaluate experience with UVA1 phototherapy for patients with cutaneous diseases in the United States. Methods: A retrospective analysis of 92 cases of UVA1-treated cutaneous conditions from four medical centers in the United States was performed. Results: Two-third of the patients showed a fair to good response (26-100% improvement) and one-third of the patients showed a poor response (0-25% improvement). Diseases with a moderate to good response (51-100% improvement) included scleredema adultorum, hand or foot dermatitis, atopic dermatitis, morphea (medium or medium- to high-dose UVA1), systemic sclerosis, and urticaria pigmentosa. Besides tanning, other adverse effects were found in 15% of patients, which include pruritus, erythema, tenderness, and burning sensation. Patients with skin types I-III responded better that those with a darker skin type. Conclusion: UVA1 phototherapy is a useful and well-tolerated treatment option for a variety of skin conditions. © 2006 Blackwell Munksgaard.