Over the past several decades, the incidence of melanoma has risen dramatically in Caucasian populations worldwide. The potential reasons for this increase in melanoma incidence are many, but the concomitant explosion in indoor tanning since the early 1980s has drawn particular scrutiny from scientists, professional societies and legislators. Ample evidence now demonstrates that indoor tanning significantly increases an individual’s risk of developing both melanoma and nonmelanoma skin cancers. Other explanations for the increasing rate of melanoma diagnosis, including increased awareness and screening, diagnostic drift, medical phototherapy use and changes in patterns of exposure to natural sunlight, are important contributing factors, but are unlikely to explain the entirety of the trend. In particular, evidence suggests that indoor tanning may have driven a spike in melanoma incidence in women and young people, among whom tanning bed use and estimated risk ratios are higher than in the general population.