Carcinoid tumors of the ovary are uncommon, but 150 cases of primary ovarian carcinoids and 40 cases of carcinoid tumors metastatic to the ovary have been reported. Primary carcinoid tumors of the ovary are divided into insular, trabecular, strumal and mucinous types. The insular type is most common, followed by the strumal type. The majority of primary ovarian carcinoids occur in association with mature cystic teratoma, but a considerable number present in pure form. Only the insular type is associated with the carcinoid syndrome. The age incidence of patients with ovarian carcinoids shows a wide range but most patients are postmenopausal. Primary carcinoids of the ovary are invariably unilateral. They form a solid nodule within a cystic teratoma, or when pure a solid yellow-grey mass, and vary from microscopical to large tumors measuring in excess of 20 cm in the longest diameter. The metastatic carcinoids are nearly always bilateral and scattered tumor deposits are present throughout both ovaries. Primary ovarian carcinoids metastasize only occasionally, and should be treated as ovarian tumors of low malignant potential.