OBJECTIVE: In recent years, mortality of preterm infants has been significantly reduced by the development of perinatal medical practices. Numerous complications may occur in these infants, including osteopenia. The aims of this study are to determine the epidemiological characteristics and risk factors of premature osteopenia.MATERIAL AND METHODS: Preterm infants who applied to neonatal intensive care unit within 6-months were enrolled in this study. The bone speed of sounds and z-scores were measured by quantitative bone ultrasonography to determine bone mineral density of the patients. The measurements were repeated once a week for 5 consecutive weeks from first week after the birth. Patients with z-score of <-1 were defined as osteopenic, while those with z-score of ≥-1 were defined as patients with normal bone mineral content. RESULTS: A number of eighty premature infants were included in the study. Gestational ages were median 33 (24-36) weeks and the mean birth weights were 1834 ± 476 grams. The bone speed of sound and z score values significantly decreased within five weeks (p<0.001). The bone speed of sound and z score were not statistically related with the number of birth, multiple gestation, presence of maternal disease and maternal drug use (p>0.05). In osteopenic cases birth weight and gestational age were found to be smaller (p = 0.042, p= 0.015, respectively). CONCLUSIONS: Osteopenia may develop in premature and very low birth weight infants despite appropriate enteral and parenteral feeding regimens. However, the risks that may be caused by other factors affecting prematurity osteopenia can be reduced by adequate vitamins and minerals.