Phototherapy is an established treatment modality for psoriasis. The use of phototherapy for psoriasis appears to be in decline in nonfederal and non-university-based settings. We used data from the National Ambulatory Medical Care Survey to estimate the number of visits for phototherapy and psoralen ultraviolet A-range (PUVA) light therapy from 1993 to 1998. There were 873,000 visits for UV light therapy in 1993-1994, 189,000 in 1995-1996, and 53,000 in 1997-1998 (P <.0001). There were 175,000 psoralen visits in 1993-1994, 61,000 in 1995-1996, and 25,000 in 1997-1998 (P =.0053). Similar decreases in phototherapy visits occurred in our university-based practice. The decline in phototherapy represents decreased utilization of a safe and effective treatment for psoriasis.