Abstract : Morel-Lavallée syndrome is a trauma that remains rare and whose management is not yet standardized. It is a closed delamination between the fascia superficialis and the cutaneous-subcutaneous tissue. This empty space is filled with fluid and may be complicated by surinfection and tissue necrosis. Regularly described in heavy traumatology, it should not be ignored in routine practice. We present the case of a regular leisure athlete with a sus-patellar syndrome of Morel-Lavalée as well as its diagnostic and therapeutic management. The evolution was favorable with a well-conducted conservative treatment. We discuss every step of the possible care in clinical practice to sensitize general practitioners to this pathology.