BACKGROUND Carcinoid heart disease typically occurs in the presence of metastatic carcinoid tumor deposits in the liver, as vasoactive substances access the systemic circulation through the hepatic vein. Primary ovarian carcinoid tumors are rare neuroendocrine tumors, and can be associated with carcinoid syndrome and carcinoid heart disease. CASE REPORT We describe the case of a 40-year-old woman who presented with secondary amenorrhea, acne, hirsutism, and diarrhea. She was found to have a heart murmur on exam in the absence of severe symptoms of heart failure. Her investigations demonstrated elevated urinary 5-hydroxyindoleacetic acid (5-HIAA), chromogranin A, and free testosterone. Abdominal computed tomography enterography showed a large and hypervascular pelvic mass. Octreotide scintigraphy confirmed the diagnosis of primary ovarian carcinoid tumor in the setting of an intensely octreotide-avid mass with no evidence of distant metastases. Transesophageal echocardiography showed severe tricuspid regurgitation with severe dilation of the right heart chambers. She underwent a total abdominal hysterectomy and bilateral salpingo-oophorectomy. The pathology demonstrated a 14-cm carcinoid tumor of ‘insular’ type confined to the ovary, pT1apNX, grade 1, positive for chromogranin and synaptophysin (neuroendocrine markers) and positive mib-1 (Ki-67). Postoperatively, clinical and biochemical parameters improved significantly but her cardiac function regressed over time, resulting in a tricuspid valve replacement 6 years later. CONCLUSIONS Primary ovarian carcinoid tumors can result in carcinoid heart disease, even in the absence of liver metastases. Early diagnosis and treatment contribute to favorable outcomes.