Background & Objective: Low birth weight is considered as one the causes of infant mortality across the world. Accordingly, paying attention to neonatal growth leads to mortality rate decrement and consequently prevents future physical and mental disabilities in this age group.
 Materials & Methods: This historic (retrospective) cohort study was conducted on 280 one-year-old male and female infants who were divided into two equal groups of low and normal birth weights. Then, the developmental status of the neonates at the corrected age of one year was assessed using the Ages and Stages Questionnaire (ASQ). Data analysis was performed using SPSS 19 via t-test and multiple regression analysis.
Results: Of the 280 infants examined, 142 (50.7%) of them were male and 138 (49.3%) were female with the mean weight of 640.9±2696.9 gr, and the mean gestational age of 37.8±2.4 weeks. Moreover, the findings revealed that the gross motor skills and the problem-solving areas had the highest levels of developmental delay in the subjects. In addition, a significant relationship was observed between the developmental delay of the neonates in different areas and the variables of birth weight, birth height, birth rate, duration of hospitalization in neonatal intensive care units (NICUs), and some causes of neonatal hospitalization (P<0.05).
Conclusion: According to the results, health policymakers were recommended to pay much more attention to the assessment of the developmental status of low-weight neonates for timely diagnosis and treatment as well as the education of health care providers and parents.