Primary ovarian carcinoid tumors are rare. It has been reported that constipation was a presenting symptom in some patients with ovarian carcinoid. A case of strumal carcinoid of the ovary with contralateral clear cell adenocarcinoma of the ovary discovered with a complaint of constipation is described. Constipation was dramatically improved by resectioning the tumor. The tumor cells were positive for peptide YY (PYY) in the carcinoid component, but not in any other components. The present case could provide evidence of the correlation between constipation and PYY that has been reported elsewhere. Interestingly, the constipation caused by PYY also helped in discovering epithelial ovarian cancer.