Objective: To describe an ovarian abscess presenting very late after oocyte retrieval for IVF with several unusual clinical features. Design: Case report. Setting: Academic medical center. Patient(s): A 35- year-old nulliparous woman underwent IVF with uncomplicated transvaginal oocyte retrieval (TVOR), resulting in a dizygotic twin pregnancy. At 13 weeks of pregnancy she presented with vaginal discharge, but was otherwise constitutionally well. At 30 weeks she developed a low-grade fever, and the diagnosis of ovarian abscess was made. She received broad-spectrum antibiotics, and the abscess was drained percutaneously after cesarean delivery of twins. Intervention(s): Antimicrobial therapy; cesarean section; postpartum percutaneous drainage. Main Outcome Measure(s): Clinical and radiologic resolution of infection. Result(s): Complete resolution of the abscess; delivery of healthy twins. Conclusion(s): Infectious complications of TVOR and other surgical procedures usually occur within days of the intervention. Our case illustrates the possibility of infectious complications of TVOR presenting months after the procedure. Our patient did not become acutely ill due to the formation of a spontaneous vaginal fistula, which allowed the abscess to drain. The optimal management of this complication is unclear, but final resolution of any pelvic abscess generally requires drainage. Objective: To describe an ovarian abscess presenting very late after oocyte retrieval for IVF with several unusual clinical features. Design: Case report. Setting: Academic medical center. Patient (s): A 35-year-old nulliparous woman underwent IVF with uncomplicated transvaginal At about 13 weeks of pregnancy she presented with vaginal discharge, but was otherwise constitutionally well. At 30 weeks she developed a low-grade fever, and the diagnosis of ovarian abscess was made. She received broad-spectrum antibiotics, and the abscess was drained percutaneously after cesarean delivery of twins. Intervention (s): Antimicrobial therapy; cesarean section; postpartum percutaneous drainage. Main Outcome Measure (s): Clinical and radiologic resolution of infection. s): Complete resolution of the abscess; delivery of healthy twins. Conclusion (s): Infectious complications of TVOR and other surgical procedures usually occur within d a patient of the intervention. Our case did not become acutely ill ill to the formation of a spontaneous vaginal fistula, which allowed the abscess to drain. The optimal management of this complication is unclear, but final resolution of any pelvic abscess requires drainage.