A 53-year-old woman with small-cell lung cancer (SCLC) presented at our hospital complaining of abdominal distention. Blood tests revealed rapidly progressive normocytic anemia and elevated lactate dehydrogenase levels. Pelvic magnetic resonance imaging revealed a left ovarian tumor and ascites. As her symptoms rapidly worsened, she underwent emergency surgery, which revealed a ruptured metastatic ovarian tumor of SCLC. Emergency surgery averted a life-threatening situation in this patient, and subsequent chemotherapy facilitated long-term survival. As seen from literature review, in female SCLC patients, ovarian metastasis and rupture is a rare but possible complication that should be considered because of its life-threatening nature.