In Brief BACKGROUND: Incarcerated uterus is a rare but serious complication. CASES: Two women presented with second trimester urinary retention. Neither received a pelvic examination at presentation, which led to a delay in diagnosing the incarcerated uterus. Patient 1 had development of acute renal failure, hypertension, and edema. After uterine reduction there was rapid normalization of renal function, hypertension, and edema, but spontaneous rupture of membranes and intrauterine death occurred 12 hours later. Patient 2 had reduction under anesthetic and subsequently underwent cesarean delivery at term. However, at 7 months postpartum, the patient continued to have high postvoid residual volumes. CONCLUSION: Women presenting with urinary retention in the second trimester should have a pelvic examination performed to exclude uterine incarceration. Earlier recognition and appropriate treatment may have altered the outcome for the two patients presented. Delayed diagnosis of an incarcerated gravid uterus leads to potentially catastrophic complications that are preventable with prompt management.