The present primary therapy of cervical intraepithelial neoplasia (CIN) grade 3 and persistent CIN 2 represents conisation. Surgical treatment can cause perioperative (infection, bleeding in in 5-10%) and postoperative (increased risk of preterm labor) complications, as well as incomplete resections (20%) and risk of recurrence in 5-17%. Imiquimod is an immunomodulating drug, that has been reported to be effective in human papilloma virus-related disease, such as vulvar intraepithelial neoplasia (VIN), vaginal intraepithelial neoplasia (VAIN), and anal intraepithelial neoplasia (AIN). The present randomised, placebo controlled, double blind study evaluates the efficacy of a topical treatment with imiquimod for 16 weeks in 60 patients with histologically confirmed CIN 2/3.