Background. Spontaneous rupture of benign uterine fibroids is extremely rare and has been associated with fibroid degeneration. It can cause acute intraperitoneal bleeding requiring immediate surgical intervention. Case. A previously healthy 50-year-old, Caucasian, nullipara presented with syncope, hemodynamic instability, and an acute abdomen. Noncontrast computed tomography images showed a positive sentinel clot sign in the pelvis as well as a large uterine fibroid with internal hyperdense clot suggesting acute rupture. Urgent laparotomy and hysterectomy confirmed a ruptured, actively bleeding, uterine fibroid with final pathological diagnosis of a benign leiomyoma. Conclusion. Prompt diagnosis and emergency surgical intervention were necessary to control acute hemorrhage from a ruptured uterine fibroid. Noncontrast computed tomography is an important adjunct to contrast-enhanced computed tomography and was vital for diagnosis in this case.