Objective: To determine the incidence of retinopathy of prematurity (ROP), and to analyze the main risk factors in premature newborns of the Hospital Lic. Adolfo Lopez Mateos. Methods: We performed a prospective study with preterm infants with < 34 weeks of gestational age and a weight < 2000 g, during the period from September 2017 to July 2018. We analyzed risk factors such as gestational age, birth weight, treatment with oxygen, sepsis, blood transfusion, surfactant use, postnatal steroid use, respiratory distress syndrome, multiple pregnancy, bronchopulmonary dysplasia, patent ductus arteriosus, intraventricular hemorrhage, and apnea episodes. We analyzed continuous and categorical variables, performed a univariate logistic regression, and calculated a multivariate logistic regression model. Results: Ninety-one premature patients were studied from which 27 had ROP (29.6%). ROP incidence was greater in patients weighing < 1300 g or with a gestational age < 29 weeks. We found a significant risk association with sepsis (Odds ratio [OR] 8.48, 95% confident interval [CI] 3.07-23.44), gestational age < 29 weeks (16.3,95% CI 4.06-65.34), and birth weight < 1000 g (OR 11.25,95% CI 2.89-43.8). Conclusions: This study demonstrates that the main risk factors for ROP are sepsis, gestational age, and birth weight. A gestational age < 29 weeks and a birth weight < 1000 g are particularly important. In a multivariate logistic regression model, sepsis and gestational age were the main factors associated with ROP. It is important to evaluate all newborns with a gestational age ≤ 34 weeks and/or weighing < 1750 g, with particular emphasis to smaller newborns.