<b><i>Background:</i></b> Pregnancy is a sex-specific risk factor for causing hemorrhagic stroke (HS) in young adults. Unique physiological characteristics during pregnancy may alter the relative risk for HS in pregnant/postpartum (PP) women compared to HS in other young women. We compared patient characteristics and HS subtypes between young non-pregnant and PP women. <b><i>Methods:</i></b> We reviewed the medical records of all women 18–45 years old admitted to our center with HS from October 15, 2008 through March 31, 2015, and compared patient characteristics and stroke mechanisms using logistic regression. <b><i>Results:</i></b> Of the 130 young women with HS during the study period, 111 were non-PP women, and 19 PP women. PP women had lower proportions of vascular risk factors such as hypertension, prior stroke, and smoking, and a higher proportion of migraine (36.8 vs. 14.4%, <i>p</i> = 0.01). After adjusting for hypertension, smoking, migraine, prior stroke and prior myocardial infarction, PP women had lower odds of having an underlying vascular lesion (OR 0.14, 95% CI 0.04–0.44, <i>p</i> = 0.0009) and a higher proportion of the reversible cerebral vasoconstriction syndrome (RCVS) as cause of their HS. <b><i>Conclusions:</i></b> Women with pregnancy-associated HS had fewer cerebrovascular risk factors, lower odds of having ­underlying vascular lesions, and higher proportion of ­migraine and RCVS compared with similar-aged non-­pregnant women. Pregnancy-associated HS appears to represent a unique pathophysiological process, requiring targeted study.