ABSTRACT Objective To calculate the frequency and evaluate the factors associated with low birth weight. Methods A retrospective study, with data from pregnant women who participated in the Programa de Atenção às Gestantes do Programa Einstein na Comunidade de Paraisópolis, between 2011 and 2014, and who returned for the postpartum evaluation of their newborns. Variables related to the pregnant woman, pregnancy, and newborn were evaluated. The outcome variable was low birth weight, defined as