BACKGROUND: Retinopathy of prematurity (ROP) is one of the leading causes of preventable childhood blindness worldwide. There has been a rapid increase in neonatal units in Tanzania leading to increased survival of preterm babies, which lead to increasing number of babies at risk of ROP. ROP screening started in Tanzania for the first time in Muhimbili National Hospital in Dar es Salaam in late 2019. This study determines the prevalence and factors associated with ROP in Muhimbili hospital from June 2020 to February 2021. METHODS: A prospective cohort study was conducted among 193 preterm newborns with ≤34 weeks gestational age and ≤2000 g birth weight. ROP screening was performed using an indirect ophthalmoscope and 20D Volk lens on dilated fundus. Prevalence was determined as the proportion of babies with ROP. Cox regression model was used to assess the contribution of risk factors to the occurrence of ROP. RESULTS: The prevalence of ROP was 29% (56/193), and of type 1 ROP was 8.8%. Majority had zone two (73.2%) and 41.1% had stage two disease. Aggressive ROP constituted 8.9%. Significant factors for ROP development were gestational age <
32 weeks (hazard ratio 6.8, p value 0.00), birth weight <
1500 g (hazard ratio 2.1, p value 0.02), Apgar score <
7 (hazard ratio 1.9, p value 0.03), RDS (hazard ratio 3.3, p value 0.01) and oxygen supplementation for >
1 week (hazard ratio 0.74, p value 0.03). Surfactant use had a protective effect (hazard ratio 0.2, p value 0.03). CONCLUSION: Prevalence of ROP is fairly high in our setting. Screening is essential to prevent visual morbidity and blindness resulting from ROP in the country.