Background: Stroke is a major cause of maternal morbidity and mortality, but delays in diagnosis are common. We hypothesize that in individuals who are pregnant or within 1 year postpartum (PP), the triad of early PP state (first 6 weeks after delivery), elevated blood pressure (BP), and headache is associated with higher stroke risk. Methods: We conducted a single-institution case-control study. Cases had a maternal stroke (ischemic, hemorrhagic, subarachnoid hemorrhage, or cerebral venous thrombosis) during pregnancy or PP, identified from a stroke registry. Controls were pregnant or PP but without any stroke and admitted for any reason, identified from a cohort of individuals with a high proportion of hypertensive disorders of pregnancy (HDP), a known maternal stroke risk factor. We created multivariable logistic regression models with stepwise backward elimination to evaluate the association between maternal stroke and the triad of (1) early PP; (2) systolic BP ≥140 or diastolic ≥90 mmHg; and (3) headache. Results: We identified 60 cases and 113 controls. Population characteristics are shown in the Table. Cases had a higher proportion of preexisting headache disorders and controls a had higher proportion of HDP. Adjusting for race, HDP, and headache disorder history, stroke risk was higher in those presenting to acute care with the proposed triad than in those without these features (adjusted odds ratio 13.6, 95% confidence interval 3.8-48.5, p<0.0001). In a predictive model, the triad exhibited excellent discrimination between cases and controls (AUC 0.82, sensitivity 30%, specificity 98%, positive predictive value 90%). Conclusions: In a high risk, diverse maternal population delivering at an urban academic medical center, the triad of early PP state, elevated BP, and headache was associated with a more than 13-fold higher risk of stroke. Patients presenting for acute care with this triad could potentially benefit from a comprehensive stroke evaluation.