Anal cancer risk is increased in certain risk groups including people living with HIV (PLWH), especially in men who have sex with men, but also in organ transplant recipients and women with a history of cervical or vulva dysplasia or cancer. High-resolution anoscopy (HRA) is a tool to diagnose anal high-grade squamous intraepithelial lesions (HSIL), and HRA-guided treatment of anal HSIL has been shown to reduce the risk of anal cancer in PLWH. The purpose of this review is to increase the awareness of HRA but also of tertiary prevention by digital anal rectal examination.