Introduction: Retinopathy of Prematurity (ROP) is the leading cause of childhood blindness in Colombia and the world. It is a preventable disease; typical to prematurity and low weight newborns. An abnormal vascular neoformation in the immature retina is induced with proliferation of capillaries that enter, in an irregular way, to the vitreous eventually causing fibrosis and retraction of the retina to the total or partial detachment of the same and subsequent neonatal blindness. Objective: Characterize the neonatal population of ROP at San Jose University Hospital (HUSJ) of Popayan, between 2012 and 2013 and to determine associated socio-demographic factors with the severity of the disease. Methods: Cross-sectional study which included: preterm infants admitted to hospital, weighing less than 1800 grams; or weighing between 1800 and 2000 grams who had risk factors; or were under 32 weeks. Pediatric ophthalmologist performed the assessment and diagnosis of newborns; the demographic and clinical characteristics were obtained on an instrument approved by experts. Statistical analysis was performed using SPSS 14.0. Results: 650 infants were admitted to the neonatal unit, of which, those who fulfilled the inclusion criteria to obtain the sample size (n = 82) were selected. 86.6% of the population came from rural areas, 61% of mothers were under 20 years, 73.2% of pregnancies were greater than 31 weeks gestation, 63.4% were male, and 74.4% weighing less than 1500 grams and 55.6% were affected until Zone II. It was found a significant association between maternal variables and degree of retinopathy as RPMO (p = 0.001), first pregnancy (p = 0.03), grade of incomplete education (p = 0.01), unemployment (p = 0.026) and rural residence (p = 0.043). On clinical features of newborns, it was found a significant association with the presence of phototherapy (p = 0.026), neonatal pneumonia (0.019), perinatal asphyxia (p = <0.001), gestational age greater than 31 weeks (p = 0.035), oxygen therapy time greater than 14 days (p = 0.003) and mechanical ventilation greater than 3 days (p = 0.019). Conclusion: More than half of children were affected until Zone II. This study suggests that low socioeconomic, educational level of mothers and clinical conditions that lead to greater exposure to oxygen therapy could be associated with the presence and degree of ROP.