Herpes simplex infections of the perianal skin and anal canal are not uncommon, as evidenced by the present series of 16 cases, but have rarely been reported in the literature of the past. They are caused by the HSV-2 virus, which is also associated with genital lesions. There is abundant evidence that anogenital herpes is a venereal disease. Anal herpes is most commonly transmitted by anal intercourse. When the infection is present inside the anal canal, especially in a primary attack, the pain can be quite dibilitating. The diagnosis can usually be made on clinical grounds by recognizing the typical vesicles or aphthous ulcers, together with inguinal lymphadenopathy. The disease is self-limiting, but may be recurrent. Asymptomatic homosexuals may represent a large reservoir of the disease, which appears to be on the increase in our society. Cytology, immunofluorescence, viral cultures and serologic tests can be used for laboratory confirmation of the diagnosis. Newer methods of treatment with vaccine containing heat-inactivated virus, and use of photoinactivation following topical application of heterotricyclic dyes, show promise.