Two cases of epithelioid leiomyosarcomas are presented. Recently epithelioid leiomyosarcomas are distinguished from the benign epithelioid leiomyosarcomas. Both benign and malignant forms of epithelioid smooth muscle tumor have been designated as leiomyoblastomas which were noncommittal term in implying either benignity or malignancy. The one of our cases was gastric epithelioid leiomyosarcoma and the other was epithelioid leiomyosarcoma of the retroperitoneum. They were composed of a mixture of round epithelioid and spindle cells, which have clear cytoplasm in many cells. The gastric epithelioid leiomyosarcoma had more than five mitoses/10 HPF, areas of compact hypercellularty of small size and 15cm in maximum diameter of the mass. Although the retroperitoneal tumor had infrequent mitoses, the tumor showed extensive necrosis and 20cm in largest diameter. These findings were considered as strongly suggestive findings of malignancy at the site of retroperitoneum. Ultrastructural findings of both tumors were some amounts of rough endoplasmic reticulum, vacuoles of varying size, fibrillar structures in the cytoplasm, and occasionally basement membrane-like structure at the cell junctions.