Leiomyosarcoma is a stromal tumor, originated from smooth muscle cells. The pathologic diagnosis represents a challenge in terms of differentiation from leiomyomas and gastrointestinal stromal tumors (GIST), defined by immunohistochemistry techniques. Its location in the rectum is extremely rare. So, management is not standardized. However, in the largest published series it was found that the abdominoperineal resection leads to better results in the prevention of local recurrence compared with local excision. We present here the case of a 44-year-old woman, whose first clinical manifestation of the disease was fever of prolonged course. A 5 cm leiomyosarcoma was diagnosed at 4 cm from the anal margin. A local transanal resection was performed. The patient is free of disease after 8 years.