The peroneal tubercle is an osseous prominence present on the calcaneus bone at the junction between the middle and the anterior third of its lateral surface. It is a bony septum which divides the tendons of the peroneus brevis and the peroneus longus and offers insertion to the inferior peroneal retinaculum. A hypertrophy of this prominence causes pain in the lateral and the posterior part of the foot while wearing shoes, rarely peroneal tenosynovitis can even cause it to break. In the following pages, we will describe a case of peroneal tubercle hypertrophy, visible even at clinical examination, in a 26-year-old male patient without apparent causes nor previous trauma.