Acute compartment syndrome of the thigh, which usually occurs in the anterior compartment, is a rare condition. It can have various causes including femur fractures, vessel injury, pseudoaneurysm of the femoral or popliteal artery, and use of anticoagulant. However, there have been few reports of acute compartment syndrome of the thigh without fracture caused by blunt trauma. We report 4 cases of acute compartment syndrome of the thigh without fracture caused by blunt trauma, in which three patients were treated with fasciotomy and a Vacuum-Assisted wound Closure system and the other one had a delayed diagnosis, and eventually underwent above-knee amputation.