Purpose: The objective of this study was to evaluate fetal and perinatal outcomes of pregnancies of adolescents and compare them with adult pregnancies. Materials and Methods: This retrospective case-control study was carried out at Bakirkoy Maternity and Children's Diseases Education and Research Hospital in Istanbul, Turkey. It enrolled 2,491 pregnancies who delivered between 2005-2010, of which 998 were adolescent pregnancies and 1,493 were adults as controls. Results: The mean age of the adolescent group was 17.10 years and in the control group the mean age was found to be 26.73 years. Intermarriage, vaginal delivery, preterm rupture of membranes, preterm birth, and preeclampsia were significantly higher in adolescent pregnancies than the control group. Gestational diabetes was more common with increasing age. There was no statistically meaningful difference between the groups in terms of intrauterine growth restriction (IUGR), low birth weight, anemia, 5-minute APGAR score, and intrauterine fetal demise. Conclusions: Young maternal age is a risk factor for preterm birth, preterm rupture of membranes, and preeclampsia. According to this study, adolescent pregnancies are more risky and more likely to have adverse fetal outcomes.