The limited published data support the assumption that lesbians are a low risk group for sexually transmitted diseases (STDs). However, there are virtually no contemporary data and the older papers do not take into account genital wart virus infection, now the third most prevalent STD in Britain. One of the dangers in assuming that lesbians are a 'safe group' for STD and allied disorders is that patients may not attend for regular cervical cytology and could be at risk of developing cervical cancer. In an unselected series of 27 lesbians attending a genitourinary medicine clinic, the most important findings were a relatively high prevalence of the viral STDs, herpes simplex and human papillomavirus. Additionally, 10 patients had abnormal cytology ranging from inflammation to dyskaryosis. There is a need for more information about the true prevalence of STDs in this group and evaluation of the risk factors for female-to-female transmission of infections. Lesbians should continue to have regular cervical smears, especially as many have had earlier heterosexual intercourse.