Inclusion Criteria:  newly diagnosed and previously untreated HSIL in women aged 18 to 35 years or up to 40 years in case of nulliparity; satisfactory colposcopy (i.e., fully visible lesion and transformation zone); negative pregnancy test; safe contraception; signed, informed consent.  Exclusion Criteria:  previously diagnosed HSIL or AIS; previous LLETZ or classical conisation; concomitant vulvar or vaginal lesion or neoplasia; other malignancies; insufficient colposcopy; pregnancy or lactation; known hypersensitivity to imiquimod; any known contraindications to immunotherapy; known HIV or acute or chronic hepatitis; immune deficiency; participation in any other ongoing clinical trial.