Background Ovarian pregnancy is a rare type of ectopic pregnancy, accounting for 0.5% to 1% of all ectopic pregnancies, with an incidence ranging from 1 in 2,100 to 1 in 60,000 pregnancies. Due to its rarity and the lack of common risk factors, diagnosing ovarian pregnancy is often challenging and typically occurs during surgical exploration. Case Presentation We present the case of a 40-year-old woman who experienced severe pelvic pain, light vaginal bleeding, and 8 weeks of amenorrhea. Upon arrival at the hospital, she was hemodynamically unstable, with low blood pressure and a rapid heart rate. An ultrasound revealed an empty uterus, an irregular mass on her right ovary, and free fluid in the pelvis. Her beta-hCG level was elevated, and her hemoglobin level was low. Given the suspicion of an ectopic pregnancy, she underwent emergency surgery. During the operation, the surgical team discovered a large amount of clotted blood and a ruptured mass on her left ovary measuring 10 x 9.5 cm. Due to heavy bleeding, they performed a left oophorectomy and salpingectomy. Histopathological analysis later confirmed the diagnosis of ovarian pregnancy. Conclusion This case underscores the challenges in diagnosing ovarian pregnancy and highlights the necessity for prompt surgical intervention, particularly in unstable patients. Early detection and appropriate management are critical to prevent life-threatening complications.