OBJECTIVE: Our goal was to evaluate an antibiotic protocol for treatment of postcesarean endometritis. STUDY DESIGN: Endometritis was diagnosed as a persistent fever ≥100.4°F beyond 24 hours after cesarean delivery and one or more of the following: uterine tenderness, tachycardia, foul lochia, or leukocytosis. Antibiotic therapy included gentamicin plus clindamycin and ampicillin (or vancomycin) as a triple antimicrobial in 148 women. Antibiotic failure was defined as persistent fever after 5 days of antibiotics and 72 hours of triple antibiotics. RESULTS: Between 1993 and 1996, 322 of 1643 (20%) women were diagnosed with postcesarean endometritis. One hundred seventy-four patients (54%) were cured with clindamycin-gentamicin, and 129 who additionally received ampicillin or vancomycin (40%) were cured. Nineteen of the 322 (6%) women had persistent fever despite triple antibiotics. Of these, 6 had a wound complication, 12 were suspected to have antimicrobial resistance, and 1 had an infected hematoma. CONCLUSION: A prospective protocol consisting of clindamycin-gentamicin plus the selective addition of ampicillin or vancomycin cured 303 of 322 (94%) women with postcesarean endometritis.