A nine year review in a Nigerian teaching hospital revealed that teenagers were responsible for 5.9 per cent of ectopic pregnancies, 14.7 per cent of spontaneous abortions, 59.9 per cent of illegal abortions and 3.7 per cent of all deliveries, and accounted for 11.5 per cent of maternal deaths. Among the teenagers whose pregnancies were carried to viability, the incidences of premature rupture of the membranes, preterm labour, pre-eclampsia and eclampsia were increased compared to the general obstetric population. Moreover, there was a higher caesarean section rate, increased low birth weight and perinatal mortality rates and a lower mean birth weight compared to the general obstetric population. The maternal morbidity and perinatal outcome were worse among the unbooked teenagers, the unmarried and among those aged 13-16 years.