Objective. To evaluate if new imiquimod formulations using a shorter treatment duration are safe and efficacious to treat anogenital warts.Methods. In two studies 534 women ≥12 years of age (mean 33.4) with 2–30 warts (mean 7.9) and total wart area≥10 mm2(mean 166.3) were randomized (1 : 2 : 2) to placebo (106), imiquimod 2.5% (212) or 3.75% (216) creams applied once daily until complete clearance or a maximum of 8 weeks.Results. For placebo, imiquimod 2.5% and 3.75%, respectively, complete clearance of all warts was achieved in 14.2%, 28.3%, and 36.6% of women (intent-to-treat,P=0.008imiquimod 2.5%, andP<0.0013.75% versus placebo). Mean changes in wart counts were −10.7%, −50.9%, and −63.5% (per-protocol,P<0.001each active versus placebo) and safety-related discontinuation rates 0.9%, 1.4%, and 2.3%.Conclusions. Imiquimod 3.75% applied daily for up to 8 weeks was well tolerated and superior to placebo in treating women with external anogenital warts.