Abdominal extra-organ mesenteric and greater or lesser omentum hemangiomas have been described, but there are no reports of peritoneal hemangioma. We report a case of a cavernous hemangioma resected from the peritoneum. The patient was a 79-year-old man who was referred to our department after CT for constipation revealed a mass inferior to the umbilicus. The 4×3 cm mass abutted the anterior abdominal wall, and small scattered calcifications were noted. Contrast-enhanced CT showed a mildly enhanced mass with irregular margins and no increase in the surrounding lipid density, suggesting a neoplastic lesion. On T1-weighted MRI, the tumor signal was equal to that of the surrounding muscle, and T2-weighted MRI showed a high signal; however, the in-phase and opposed-phase contrast suggested the presence of internal fat. We suspected an intra-abdominal neoplastic lesion and opted for resection. The tumor was contiguous to the anterior abdominal wall, with no adhesion to the surrounding organs, and was resected with the anterior abdominal wall, rectus abdominis, and skin. The cut surface of the tumor was spongy and the tumor was soft. Histopathology revealed a diagnosis of cavernous hemangioma. Peritoneal origin was suggested since the tumor was firmly adherent to the peritoneum, with no extraperitoneal neoplastic lesions, such as in the rectus muscle or preperitoneal fat. We report this case as a rare example of a peritoneal cavernous hemangioma. This disease could be considered as a differential diagnosis in cases with similar imaging findings.