OBJECTIVE: To analyze the association of characteristics recorded at the time of birth, including weight, occurrence of asphyxia, gestation duration, maternal age and education level, with death from diseases or malformations of the circulatory system in children under 18 years of age. METHODS: The Brazilian Information System on Live Births and Information System on Mortality databases were linked and evaluated following a longitudinal cohort analysis strategy. The following independent variables were evaluated: characteristics recorded at the time of birth, including weight, occurrence of asphyxia, gestation duration, maternal age and education level. Dependent variables were death from diseases or malformations of the circulatory system in children under 18 years of age. Crude relative risks were estimated and relative risks were adjusted for the variables. RESULTS: 6,380 deaths were linked to 4,282,260 birth records, yielding 5,062 pairs considered as true. Low birth weight (RR = 2.26), asphyxia at 1 (RR = 1.72) and 5 minutes (RR = 1.51), prematurity (RR = 1.50), maternal age ≥ 40 years (RR = 2.06), and low maternal education level (RR = 1.45) increased the probability of death caused by circulatory system diseases. In the association with death by malformations of the circulatory system, the predictive variables showed the same association profile, but with greater intensity. CONCLUSIONS: Fetal and maternal factors are associated with increased mortality due to diseases and malformations of the circulatory system. Measures to control these factors and improve access to their diagnosis and treatment would contribute to reducing the number of deaths caused by diseases and malformations of the circulatory system. However, the identification of environmental influences during gestation and birth on the risk of death should be carefully considered due to being influenced by genetic factors.