A 23-year-old female was referred with constipation that lasted for 2 years. Preoperative examinations revealed multiple submucosal tumors beside the anorectum, along with subcutaneous tumors in the left buttock. The pathological diagnosis was leiomyoma. Low anterior resection of the rectum with regional lymph node dissection, along with the resection of the subcutaneous tumors in the left buttock through the transdermal approach, was performed, since multiple tumor formation indicated a high malignant potential. The tumors were diagnosed as multiple leiomyomas with no malignancy. Disease categories such as intravenous leiomyomatosis, leiomyomatosis peritonealis disseminata, Alport syndrome, and Currarino syndrome have been reported to be associated with leiomyomatosis; however, the current case of "peri-anorectal leiomyomatosis" was not classified into any of these. The patient was monitored with careful checkups, and the postoperative course was satisfactory for over 5 years without any sign of recurrence or metastasis. Although the clinicopathological features of this case are quite rare and no therapeutic guidelines for such a disease have yet been established, radical resection should be considered, and the elucidation of the histogenesis of this disease will help establish future therapeutic guidelines.