Use of artificial tanning devices that emit UV radiation, such as tanning lamps and tanning beds, has become increasingly popular in the United States. Although an excess risk of nonmelanoma skin cancers might be predicted from this exposure, little epidemiologic data exist. We conducted a population-based, case-control study that included 603 basal cell carcinoma (BCC) case patients, 293 squamous cell carcinoma (SCC) case patients, and 540 control subjects. Study participants were interviewed in person to obtain information on tanning device use, sun exposure history, sun sensitivity, and other risk factors for skin cancer. Overall, any use of tanning devices was associated with odds ratios of 2.5 (95% confidence interval [CI] = 1.7 to 3.8) for SCC and 1.5 (95% CI = 1.1 to 2.1) for BCC. Adjustment for history of sunburns, sunbathing, and sun exposure did not affect our results. Our findings suggest that the use of tanning devices may contribute to the incidence of nonmelanoma skin cancers. They highlight the need to further evaluate the potential risks of BCC and SCC that are associated with tanning lamp exposure and the appropriate public health response.