Objective: We examined the relation of maternal sociodemographic, medical, and behavioral characteristics with risk of abruptio placentae in Peruvian women. Study design: This case-control study included 255 abruptio placentae cases and 258 pregnant controls. Multivariable logistic regression models were fit to calculate odds ratios (OR) and 95% CIs adjusted for putative abruptio placentae risk factors. Results: History of delivering a stillborn infant (OR 10.0; 95%CI 4.0-25.2), pregnancy complicated by preeclampsia/eclampsia (OR 3.7; 95%CI 2.2-6.3); and a low rate of pregnancy weight gain (<0.15 kg/wk) (OR 2.5; 95%CI 1.3-4.7), were associated with significantly increased risk of abruptio placentae. Advanced maternal age, low educational attainment, male infant gender, cigarette smoking, and grand multiparty were not risk factors of abruptio placentae in this population. Conclusion: At present, the constellation of abruptio placentae risk factors do not provide clinically meaningful opportunities for identifying high-risk patients. © 2006 Mosby, Inc. All rights reserved.