The drugs taken by patients with suspected cutaneous drug reactions (CDR) were recorded during a 4-year period at Sahlgren Hospital in Gotenburg in a prospective study. A total of 440 patients were included. By dividing the frequency of occurrence of the recorded drugs by the number of sold defined daily doses (SDDD) for the city during the same period of time, figures for the CDR risk for different drugs corrected for frequency of use were obtained. The risk of CDR seemed to be highest for gold compounds, trimethoprim with and without sulphonamides, cephalosporins and penicillins. The most common types of CDR were macular and mucalopapular eruptions, followed by urticaria and cutaneous vasculitis. The results correlate well with those of the Boston Collaborative Drug Surveillance Program.