Topical tacrolimus ointment was approved for the treatment of atopic dermatitis in Japan in 1999, the United States in 2000, and Europe in 2001. The safety and efficacy of tacrolimus ointment was established in vehicle-controlled, randomized, 12-week clinical trials; 1-year open-label trials; and comparative studies with topical steroids. Although an extensive database exists on the safety and efficacy of tacrolimus ointment based on the global development program, clinicians desire additional information on the long-term safety and efficacy of this novel agent. In this supplement, additional studies are reported that extend the safety and efficacy profile of tacrolimus ointment in patients with atopic dermatitis, including long-term safety studies for up to 4 years. The studies presented in this supplement address important questions regarding the selection and use of tacrolimus ointment in the treatment of patients with atopic dermatitis.