The first case report of a 58-year-old woman with two different primary carcinoid tumors is presented. The bronchial carcinoid exhibited a mosaic pattern, whereas the ovarian tumor showed both insular and trabecular patterns. No teratomatous component was observed in the ovary. Both tumors presented an argyrophil reaction and neuron-specific enolase (NSE) immunoreactivity. The ovarian carcinoid contained a cell population of argentaffin and serotonin immunoreactive cells, while the bronchial carcinoid was unreactive. Peptide hormone immunostaining disclosed the presence of glucagon and pancreatic polypeptide (PP) in the bronchial carcinoid, whereas the ovarian carcinoid showed no immunoreactivity with the antisera used. The patient was treated surgically (bilobectomy of the right lung, 1978, and total abdominal hysterectomy and bilateral salpingo-oophorectomy, 1984) and is now well with normal blood chemistry, normal urinary HIAA, and normal routine X rays of the lungs and the gastrointestinal tract, as well as normal ultrasonography of the abdomen and the liver.