Imiquimod is a topical preparation, which has been shown to induce local immune response. It stimulated the production of interferon and other cytokines important in cell-mediated local immune response, which can promote antiviral and antitumour effects. A previous study, published in 2001, looked at the effect of imiquimod in treating superficial BCC. The present study looked at two phase-2 studies, a 6-week randomized, open-label, dose–response study evaluating four dose regimens and a 12-week, randomized, vehicle-controlled, double-blind, dose–response study also evaluating four dose regimens. In the 12-week vehicle-control study 92 and in the 6-week study 99 white patients were enrolled. There were maximum clearance rates of 76% in the 12-week study group compared to 71% clearance in the once daily, 7-day group in the 6-week study. However, the 6-week treatment was shown to be better tolerated by patients and had a lower incidence of severe local skin reactions, total adverse events and need for rest periods.