Compartment syndromes of the thigh after blunt trauma without any fracture are rare. Most surgeons recommend operative treatment. There are different rules for compartment syndromes of the thigh in young athletes after blunt trauma compared to compartment syndromes at other locations [(1) the large volume of the quadriceps muscle, (2) its relatively elastic fascia, (3) the direct proximal contact to the hip muscles which allows extravasation of fluid out of the compartment)]. We present a case of conservative treatment of elevated intra-compartmental pressure (ICP) of the anterior thigh after blunt trauma and the follow-up until return to sport. Conservative treatment of a compartment syndrome of the thigh after blunt trauma in a young patient without fracture or vascular damage was successful without short-term sequelae. Recovery of muscle strength is delayed but return to sport is possible. Depending on the severity the diagnosis and follow-up with ICP measurements and MRI is necessary. There is a very good chance for excellent outcome without any risk of surgery. However, a long healing time is possible.