PURPOSE: Indoor tanning usually begins during adolescence, but few strategies exist to discourage adolescent use. We developed and tested a parent-teenager intervention to decrease indoor tanning use. METHODS: Through focus groups, we identified key messages to enhance parent-teenager communication about indoor tanning, and then developed a pamphlet for parents and postcards for adolescents to use in a direct mail experiment with randomly selected households. Two weeks after the mailing, we asked intervention parents (n = 87) and adolescents (n = 69) and nonintervention parents (n = 31) and adolescents (n = 28) about intervention receipt and content recall, parental concern, monitoring, parent-teenager conversations, and indoor tanning intention. RESULTS: In intervention households, 54% of mothers and 56% of girls recalled receipt and reported reading materials, but few boys and no fathers did. Among mothers, 57% in intervention households indicated concern about daughters' indoor tanning, and 25% would allow daughters to tan indoors, whereas 43% of nonintervention mothers had concerns and 46% would allow indoor tanning. Fewer girls in intervention households than in nonintervention households thought parents would allow indoor tanning (44% vs. 65%), and fewer intended to tan indoors (36% vs. 60%). Most mothers and daughters who read the intervention materials also reported discussions about indoor tanning. Moreover, the less likely girls were to think that their mothers would allow indoor tanning, the less likely it was that they intended to tan indoors, a relationship mediated by perceptions of maternal monitoring. CONCLUSIONS: A systematic qualitative and quantitative research approach yielded well-received indoor tanning prevention messages for mothers and female adolescents. Enhancing maternal monitoring has potential to decrease adolescent indoor tanning.