Abstract Background The poor eating habits of children, including a decrease in the consumption of unprocessed foods and an increase in the consumption of processed foods, have been associated with excess body weight, which is a well-established risk factor for cardiovascular diseases (CVDs), especially high blood pressure (BP). We aimed to investigate whether the consumption of unprocessed and minimally processed foods is associated with high BP in children at nine years of age. Methods Cross-sectional study of 142 Brazilian children participating in a cohort study conducted at the participant’s home. The child’s food consumption markers were evaluated using the Brazilian Food and Nutrition Surveillance System (SISVAN) and were classified by NOVA. Using a standardized procedure for approaching the child, BP was measured by the auscultatory method. Biological, socioeconomical, demographic, and anthropometric data of the mother and child were also collected. Logistic regression analysis adjusting for important predictors was used to evaluate the association between food consumption and BP. Results The prevalence of high BP in children was 20.4%, and the mean systolic and diastolic BP were significantly (p < 0.05) higher in children classified as high BP (110.1 and 71.3 mmHg, respectively). An important proportion (44.8%) of children had excess body weight (>85th percentile) and high BP when compared to eutrophic children. Not consuming healthy foods was associated with high systolic BP, even after adjustment for other important covariates (OR = 3.97; p = 0.028). Conclusions Not consuming healthy foods was associated with increased odds of children having high BP at nine years of age. Interventions promoting a healthy diet and the consumption of fruits and vegetables in childhood may contribute to preventing diseases associated with CVD, a global public health problem. Key messages • Educating parents to avoid processed foods and monitoring children’s BP are essential actions to prevent associated chronic diseases throughout life. • Public policies aimed at educating parents to encourage the consumption of healthy foods may significantly contribute to reducing adverse cardiovascular outcomes.