BACKGROUND: Monthly thorough skin self-examination (TSSE) is an important practice for early melanoma detection that is performed by a small minority of the population. DESIGN: A randomized trial was conducted to determine whether a multicomponent intervention can increase TSSE performance and to describe the effects on performance of skin surgeries compared with a similar control intervention focused on diet. SETTING/PARTICIPANTS: One thousand three hundred fifty-six patients attending a routine primary care visit in southeastern New England participated in this trial. INTERVENTIONS: Participants received instructional materials, including cues and aids, a video, and a brief counseling session and (at 3 weeks) a brief follow-up phone call (from a health educator) and tailored feedback letters. MEASURES: Performance of TSSE assessed by telephone interview and having a surgical procedure performed on the skin were confirmed by examining medical records. RESULTS: TSSE was performed by substantially more participants at 2, 6, and 12 months in the intervention group than in the control group (55% vs 35%, p<0.0001 at 12 months). We also noted that a substantially higher proportion in the intervention group had skin surgery in the first 6 months (8.0% vs 3.6%, p=0.0005), but there was no difference at 6 to 12 months (3.9% vs 3.3%, p=0.5). CONCLUSIONS: The TSSE intervention was effective in increasing performance of TSSE, in that it resulted in increased surgery on the skin, and that increase in skin procedures only persisted for 6 months. Intervention to increase TSSE may result in long-term benefit in early detection of melanoma while causing only a short-term excess of skin surgeries.