Involvement of skeletal muscle in Eccinococcal infection is a relatively rare condition which clinically mimics soft tissue tumors at initial presentation. We present a case report of a 30 years old female patient presented with a painless mass on anterolateral region of her left thigh. Diagnostic work up begun with an MRI examination and it revealed a mass containing multiple cystic vesicles in vastus lateralis muscle which was identical to hydatid disease those seen elsewhere in human body. Surgical excision with Albendazole medication cured the patient. Hydatid disease may present as a painless mass in extremities thus it should be included in differential diagnosis of such masses especially in endemic areas.