Muscular hydatid cyst is a rare condition mainly secondary to the cysts from other organs. We hereby present an uncommon case of primary hydatid cyst found in the right biceps brachii muscle of a 36-year-old male. Magnetic resonance revealed no Echinococcus involvement in any other part of his body. Chest X-ray was normal, and no trace of cyst was found in the lung. In areas where echinococcosis is endemic, any tumor or mass in any part of the patient's body should be evaluated and examined for Echinococcus infestation. This paper is the second case report article on echinococcal biceps brachii infestation existing to this date.