Abstract. This article discusses low birth weight infants and the causes, morphological characteristics, and functional features of premature birth. Prematurity and low birth weight remain major challenges in neonatal healthcare and are among the leading causes of neonatal morbidity and mortality worldwide. The study analyzes the maternal, fetal, and environmental factors associated with premature birth and examines the physical and physiological characteristics of low birth weight newborns. Particular attention is given to the immaturity of organ systems, including the respiratory, cardiovascular, digestive, nervous, and immune systems. The article also highlights the complications associated with prematurity and emphasizes the importance of early diagnosis, specialized neonatal care, and preventive measures. The findings demonstrate that comprehensive management and modern neonatal interventions significantly improve survival rates and long-term developmental outcomes in premature infants.