Cowden disease, also known as multiple hamartoma syndromes, is an autosomal dominant disease characterized by numerous benign mucocutaneous tumors, hamartomas of multiple organs, and malignancies of the breast and thyroid. In this report, we present the computed tomographic findings in three patients with Cowden disease. In addition to the classic findings, the patients were diagnosed with spinal neurinoma (n = 1), meningioma (n = 1), and hepatic hemangioma (n = 3). We also review current clinical and genetic concepts that unify Cowden disease.