We report one rare case of overriding impacted symphysis by lateral compression injury of the pelvis. A 21-year-old male presented a disruption of the pubic symphysis following a car accident with lateral injury. The patients radiographs revealed a displacement of the left part of the symphysis behind the right one and sacro-iliac disruption. CT scan confirmed a left posteriorly displaced pubic symphysis and a right sacro-iliac disruption without any fracture There were no additional injuries. Open reduction and internal fixation was necessary to reduce displacement and fixation of the pubic symphysis with a plate, and screwing of the right sacroiliac disjunction. One year after injury,there was no pain in the pelvis,urinal and sexual function were normal. This lesion is secondary to lateral compression injury with internal rotation of the left part of the pelvis. It can be classified in the type B2 of Tiles classification. It is a rare condition because this mechanism very often leeds to a fracture of the pelvic ring.