A case report is presented that gives new insight into a very rare cause of athletic pubalgia. Up till now, no case has been published in literature about the relevance of an arcuate pubic ligament (APL) injury in athletic pubalgia. The APL or inferior pubic ligament is a thick triangular arch of ligamentous fibers connecting the 2 pubic bones below. The main function of the APL is to stabilize the symphysis pubis. The rupture of this ligament can lead to groin pain due to lack of stabilization of the symphysis pubis. Despite the importance of the anatomical and clinical function of the APL, very limited research is available about injuries of this ligament. This report describes a case of a traumatic left APL rupture, confirmed by magnetic resonance imaging, causing longstanding left groin pain in an amateur athlete.