The current methods of diagnosing and treating herpes genitalis in clinics for sexually transmitted diseases in England and Wales are reported. Virus cultures were used as a diagnostic test in some or all patients in nearly two-thirds of clinics. Darkground examinations were performed on all or selected patients in most clinics, but fewer than half the clinics performed them on three or more separate occasions. In over 80% of clinics attempts were made to see some or all contacts of patients with herpes. The treatments prescribed varied, the commonest being saline washes, idoxuridine, and oral antibiotics. Serological tests were repeated after the disappearance of the lesions in 90% of clinics, while in 60% of clinics women with herpes genitalis were advised to have cytological examination at regular intervals in future. The importance of excluding syphilis in patients presenting with genital ulceration, the most appropriate treatments for herpes, and the possible association between the disease and cervical carcinoma are discussed.