Objective: To examine the impact of a skin cancer prevention intervention that promoted sunless tanning as a substitute for sunbathing.

Design: Randomized controlled trial.

Setting: Public beaches in Massachusetts.

Participants: Women (N = 250) were recruited to participate in the study during their visit to a public beach.

Intervention: The intervention included motivational messages to use sunless tanning as an alternative to UV tanning, instructions for proper use of sunless tanning products, attractive images of women with sunless tans, a free trial of a sunless tanning product, skin cancer education, and UV imaging. The control participants completed surveys.

Main Outcome Measures: The primary outcome was sunbathing 2 months and 1 year after the intervention. Secondary outcomes included sunburns, sun protection use, and sunless tanning.

Results: At 2 months, intervention participants reduced their sunbathing significantly more than did controls and reported significantly fewer sunburns and greater use of protective clothing. At 1 year, intervention participants reported significant decreases in sunbathing and increases in sunless tanning relative to control participants but no differences in the other outcomes.

Conclusion: This intervention, which promoted sunless tanning as an alternative to UV tanning, had a short-term effect on sunbathing, sunburns, and use of protective clothing and a longer-term effect on sunbathing and sunless tanning.

Trial Registration: clinicaltrials.gov Identifier: NCT00403377