Over a 12 month period, 32 teenage girls attended the sexually transmitted disease clinic in the Mater Misericordiae Hospital, Dublin for the first time, accounting for 17.8% of all first visits. Their mean age was 18.2 years (range 15-19 years). Twenty-four (75%) were from social class V. Five (15.6%) were abusing drugs. The mean age of first coitus was 16.1 years (range 13-19 years). The mean number of sexual partners was 1.8 (range 1-5). Four (12.5%) had been sexually abused in the past. Fourteen (43.8%) had never used contraception. Twenty-three (71.9%) were nulligravidae: 2 were diagnosed as being pregnant in the clinic. Twelve (37.5%) were unaware of cervical cytology screening. Of 29 having intercourse without condoms, none considered themselves to be at risk of contracting HIV from their present partner. A total of 26 diagnoses were made in 23 patients (71.9%). The most common diagnosis was ano-genital condylomata acuminata (6, 18.8%); Chlamydia trachomatis was located in 2 patients and Neisseria gonorrhoea in one. Mild to moderate dyskaryosis was reported in 4 cervical smears (12.5%). This data highlights the need for priority targeting of this high risk group.