The first example of mixed strumal and mucinous carcinoid tumor of the ovary is reported. The vast majority of the tumor was composed of carcinoid cells arranged in a trabecular-insular configuration admixed with obvious thyroid follicles. In addition, glands lined by mucin-producing cells were seen in some areas. A transition from the strumal carcinoid component to the mucinous glands was seen. Immunohistochemical studies showed that the strumal and mucinous carcinoid components were positive for chromogranin A, serotonin, and vasoactive intestinal polypeptide, clearly demonstrating that both were neuroendocrine in nature.