Adverse drug reactions reported to the Norwegian Medicine Control Authority from 1970 to 1994 were analyzed, especially with regard to cutaneous reactions and photosensitization. In the time period, almost 13,000 unwanted side effects were reported. Of these, 799 reports involved the skin and appendages, of which 64 reports (8%) were classified as photosensitivity reactions. Tetracyclines, diuretics, antihypertensive agents, and urologicals were the drugs that most often caused photosensitivity reactions. In addition, a number of uncommon photosensitizing drugs were reported. The risk for photosensitization is discussed on the basis of experimental data and the prescription rates of these substance.