Adolescent pregnancy is the pregnancy of girls aged 10-19 years, leading to many maternal and neonatal adverse effects. These pregnancies have been a global concern for many decades and yet are still prevailing. This article has reviewed the significant determinants of adolescent pregnancy and various maternal adverse effects, including preeclampsia, preterm premature rupture of the membrane (PPROM), maternal anemia, sexually transmitted diseases, postpartum depression, and maternal deaths, and adverse neonatal outcomes, including low birth weight (LBW), prematurity, stillbirths, early neonatal demise, and low Apgar score. Various pathophysiologic events that lead to such adverse consequences have been briefly discussed in the article and how such occurrences can be overcome. This article has also emphasized the need to implement various modalities such as sex education, availability of contraceptives, and bringing community-level awareness to lower the prevalence of adolescent pregnancy.