OBJECTIVE: To evaluate the efficacy of duct tape occlusion therapy for the treatment of common warts in adults. DESIGN: Double-blind controlled clinical intervention trial. SETTING: Veterans Affairs medical center. PARTICIPANTS: A total of 90 immunocompetent adult volunteers with at least 1 wart measuring 2 to 15 mm were enrolled between October 1, 2004, and July 31, 2005. Eighty patients completed the study. INTERVENTION: Patients were randomized by a computer-generated code to receive pads consisting of either moleskin with transparent duct tape (treatment group) or moleskin alone (control group). Patients were instructed to wear the pads for 7 consecutive days and leave the pad off on the seventh evening. This process was repeated for 2 months or until the wart resolved, whichever occurred first. Follow-up visits occurred at 1 and 2 months. MAIN OUTCOME MEASURE: Complete resolution of the target wart. Secondary outcomes included change in size of the target wart and recurrence rates at 6 months for warts with complete resolution. RESULTS: There were no statistically significant differences in the proportions of patients with resolution of the target wart (8 [21%] of 39 patients in the treatment group vs 9 [22%] of 41 in the control group). Of patients with complete resolution, 6 (75%) in the treatment group and 3 (33%) in the control group had recurrence of the target wart by the sixth month. CONCLUSION: We found no statistically significant difference between duct tape and moleskin for the treatment of warts in an adult population.