Background Bronchopulmonary dysplasia (BPD) is one of the most common serious squeal of preterm infants. It involves approximately one quarter of infants with birth weight less than 1500 grams and 30% of less than 1000 grams. Vitamin A has been shown to reduce BPD rate. We compared efficacy of low and high doses of vitamin A for prevention of BPD in very low birth weight preterm infants. Materials and Methods In a randomized clinical trial, 120 preterm infants with gestation age 32 weeks or less and birth weight less than 1,500 grams were enrolled in the study. Group A (n=60) received 1,500 IU vitamin A intramuscularly three times per week and group B (n=60) received 5,000 IU vitamin A intramuscularly 3 times/week. Vitamin A was continued for 4 weeks in all patients. Oxygen dependency at age 28 days after birth and at 36 weeks’ postmenstrual age was determined in all studied infants. Results The mean gestation age and birth weight in group A was 29.2 ± 2.1 weeks and 1095 ± 211 gr and in group B 28.7 ± 2.1week and 1147 ± 218 grams (P>0.05). Moderate to severe bronchopulmonary dysplasia was detected in 6 (10%) neonates in group A and 13(21.6%) infants in group B, P= 0.09. Mortality rate was 4 (6.6%) infants in group A and 3 (5%) patients in group B (P>0.05). Conclusion In our study, high and low doses of vitamin A were similar with respect to the BPD, intra-ventricular hemorrhage, and retinopathy of prematurity and total number of days for hospital stay in very low birth weight preterm infants