Small-cell lung carcinoma with ovarian metastasis 4 years after the first-line treatment Abstract Small-cell lung carcinoma rarely metastasizes to the ovary. Only few cases of this condition have been reported to date. A 42-year-old female nonsmoker was an outpatient after receiving treatment for small-cell lung carcinoma. Approximately 45 months after the first-line treatment, the pro-gastrin-releasing peptide level exhibited a gradual increase. Positron emission tomography-computed tomography revealed abnormal accumulation in the left ovary. Accordingly, we performed laparoscopic salpingo-oophorectomy. Both pathological and immunohistochemical examinations (thyroid transcription factor-1, synaptophysin, and chromogranin A staining) led to the diagnosis of ovarian metastasis of small-cell lung carcinoma. The pro-gastrin-releasing peptide level declined postoperatively, and no recurrence has been reported thus far. Here we reported an extremely rare case of small-cell lung carcinoma metastatic to the ovary after several years of receiving the initial treatment for small-cell lung carcinoma, which, however, exhibited an excellent course postoperatively.