Background: Teenage pregnancy due to changing social conditions, it’s important to study the implications of the maternal and fetal health. It is a serious health problem, more so in developing countries like India. Aim: To assess the fetomaternal outcome in teenage pregnancy. Material and methods: This was a prospective observational study conducted in the department of gynaecology and obstetrics in Patna medical college and Hospital, Patna, Bihar, India, for 12 months from July 2019 to July 2020. It included 50 cases of primigravida teenage pregnancies and 50 cases of adult pregnancies. Primigravida teenage mothers aged 13-19 years were taken as case and primigravida adult mothers aged20-30 years were taken as control. Results: The results show maximum number of teenage mothers belonged to the age group of 16-19 years (98%). In teenage mothers more cases (56%) were related to lower socio economic status than adult mothers (28%). The study shows that majority of cases (74%) of teenage mothers were illiterate as compared to adult mothers in which 26%were illiterate and shows that ante partum & postpartum complications were much higher in teenage mothers as compared to adult mothers. In our study antenatal complications were higher among teenage mothers as compared to adult mothers. Conclusion: Prevention of teenage pregnancy and reduced complications of teenage pregnancy can be achieved by improving the utilization of family planning services to reduce the rate of teenage pregnancies and minimizing their hazards and to prevent further pregnancies (by post-partum IUCD).