Introduction: Low birth weight and preterm birth are the major community health problems in developing countries. They are the major determinants of perinatal survival and infant morbidity and mortality. The aim of this study was to determine the proportion and the maternal risk factors for low birth weight and preterm birth among hospital deliveries in Tribhuvan University Teaching Hospital. Methods: A cross sectional retrospective study was carried out in the Department of Obstetrics and Gynecology of TUTH. Maternal risk factors like age, parity, ethnicity, history of previous abortion, history of previous cesarean section, antepartum hemorrhage and medical disorders were studied. Information on all births that occurred was extracted from maternity case notes and delivery registers.  Results: During the study period, there were 685 singleton live births. Among these 78(11.4%) were low birth weight and 47(6.9%) were preterm birth. The mean birth weight was 2950±488 gm. The mean weight of female was statistically less compared to male babies (p=0.032). The signi cant risk factors for LBW were primiparity (OR 2.12; 95%CI 1.25-3.58), Indo-Aryan ethnicity (OR 1.97; 95%CI 1.12-3.45) and history of medical disorder (OR 3.08; 95%CI 1.17-8.12). As for PTB antepartum hemorrhage (OR 8.63; 95%CI 1.99-37.30) and history of medical disorder (OR 3.20; 95%CI 1.04-.89) were signi cant risk factors.  Conclusions: Parity, ethnicity, and medical disorders were the main risk factors for low birth weight. Antepartum hemorrhage and medical disorders were signi cant risk factors for preterm birth. Keywords: low birth weight; preterm birth; risk factors.