Patients treated with glucocorticoids may have an increased risk of skin cancer. Using data from the population-based North Jutland Prescription Database and the Danish Cancer Registry, we compared observed and expected numbers of cases of skin cancer and non-Hodgkin lymphoma among 59 043 individuals who received prescriptions for glucocorticoids, a common immunosuppressive therapy, during an 8-year period from January 1, 1989, through December 31, 1996. The overall risks for squamous cell carcinomas and basal cell carcinomas of the skin were increased, particularly among persons who had 15 or more prescriptions (standardized incidence ratio [SIR] for squamous cell carcinomas = 2.45, 95% confidence interval [CI] = 1.37 to 4.04; SIR for basal cell carcinomas = 1.52, 95% CI = 1.09 to 2.07). An elevated risk was also found for non-Hodgkin lymphoma among those with 10-14 prescriptions (SIR = 2.68, 95% CI = 1.16 to 5.29). Our data suggest that use of glucocorticoids may be a shared risk factor for certain skin cancers and lymphomas.