Acute muscle lesions are frequent conditions in sports traumato-logy. Intrinsic traumatic mechanism (excessive stretch) is more prevalent that extrinsic mechanism (direct shock or lacerations). The diagnosis is generally based on the injury mechanism description together with the clinical examination. The ultrasonography is helpful in order to evaluate the severity of the lesion and the time to sports resumption. The initial management is based on the POLICE acronym: Protection, Optimal loading, Ice, Compression, and Elevation. For high grade muscle lesions, patients might benefit from either ultrasound-guided hematoma evacuation or surgical repair. Non-steroid anti-inflammatory drugs should be avoided within the first days. The rehabilitation should begin 48h after the trauma, whatever the severity of the lesion.