Lymphogranuloma venerum (LGV), previously lymphogranulma inguinale, is a sexually transmitted infection caused by Chlamydia trachomatis serovar L1-L3. The disease is primarily manifested by a small papule or erosion in the genital region, followed by lymphadenitis and development of abscesses. Proctitis and systemic disease may occur subsequently. LGV has been a rare condition in the western world, but there have been frequent reports from larger cities in Europe and the USA from 2004. Outbreaks have been limited to networks of gay men practising mano-brachial sex ("fisting"). The syndrome may easily be confused with chronic diseases of the gut, bacterial infections and other sexually acquired diseases. We present two HIV-positive gay men where lymphogranuloma venerum was found to be the cause of ulcerative proctitis. The diagnosis was confirmed by a positive Chlamydia test from the anus with subsequent subtyping.