To determine the association between the ABO blood group and preeclampsia.This is a case-control study that included patients with (n = 253) and without (n = 457) preeclampsia/eclampsia in Northeastern Mexico. Data were obtained from electronic medical records. Binary multiple logistic regression analysis was used for analyzing the association between the ABO blood group and preeclampsia according to parity status while adjusting for potential confounders.Blood groups A, B, and AB showed adjusted odds ratios of 0.6 (95%CI 0.3-1.0), 1.1 (95%CI 0.6-2.2), and 0.3 (95%CI 0.1-1.1) in multiparous women, respectively. No association was found in nulliparous women either.ABO blood groups were not associated with preeclampsia in Mexican women. [Figure: see text].