Study objective To determine specific risk factors that increase the failure rate of labor epidurals reactivated for use as a surgical block for postpartum tubal ligation. Design Prospective, observational study. Setting Labor and delivery suite and operating rooms at the Women and Infants Center. Patients One hundred patients undergoing postpartum tubal ligation with an existing labor epidural that is documented to be within 2 cm of initial placement. Measurements Body mass index, patient satisfaction with her epidural during labor and delivery, time from delivery to reactivation for tubal ligation, depth to loss of resistance, and the need for top-ups during labor were recorded preoperatively. Failure to reactivate was recorded and defined as any patient that (1) did not achieve a T6 level to pinprick, (2) had perceived pain (pain score >3) that required administration of an intravenous opioid or local anesthetic infiltration, or (3) required conversion to general anesthesia. Main results The overall success rate of reactivation was 78%. Significant risk factors for failure to reactivate were (1) poor patient satisfaction (P =.016), (2) increased time from delivery to reactivation (P =.044), and (3) the need for top-ups during labor and delivery (P =.032). Conclusion Poor satisfaction score of the epidural during labor and delivery, increasing time from delivery to epidural reactivation for tubal ligation, and the need for top-ups during labor and delivery increase the incidence of reactivation failure. No correlation was found with body mass index or loss of resistance and failure to reactivate.