INTRODUCTION: Postpartum emergency department (ED) visits complicate 12% of births. We aimed to characterize trends in ED visits and risk factors for readmission. METHODS: This was a retrospective cohort study on postpartum ED visits within 42 days of delivery at a tertiary care center over 1 year. Readmitted patients were compared to those who remained outpatient as appropriate. IRB #14-001098. RESULTS: Of 3,084 deliveries, 138 (4.5%) patients presented to the ED for total 157 encounters. 17 (12.3%) patients presented more than once. 55 (35%) ED visits resulted in readmission, with 4 patients readmitted twice. Public insurance rates in the cohort were significantly higher than baseline (16.7% versus 8.5%, P=.001). Postpartum hypertension (HTN) was the most common reason for ED visits (40%) and had four times higher likelihood of being readmitted (adjusted odds ratio [aOR] 4.076, 95% CI 2.04–8.15, P<.001). Black women were six times more likely to be readmitted compared to other groups (aOR 6.53, 95% CI 1.26–33.88, P=.026). Coexistent psychiatric disease had lower likelihood of readmission (aOR 0.43, 95% CI 0.19–0.95, P=.037). Having more than one ED visit led to fivefold higher odds of readmission (aOR 5.05, 95% CI 1.66–15.32, P=.004). Median days from delivery to ED visit were 8 (interquartile range [IQR]: 5, 15). CONCLUSION: Seventy-three percent of presentations to the ED were within 2 weeks of delivery, and postpartum HTN was the leading cause. Black patients were more likely to be readmitted. Further studies are needed to evaluate whether earlier postpartum visits for high-risk groups may reduce ED visits and readmissions.