Ganglion cysts that compress the common peroneal nerve frequently arise from the proximal tibiofibular joint. We report three cases of such ganglia. In one case the ganglion cyst arises from the proximal tibiofibular joint, finds its course along the common peroneal nerve causing pain, but no neurological deficit. In the two other cases the cysts have the same origin but they are the cause of a progressive peroneal nerve palsy. Treatment in these three cases was successful resection of the cyst with non mutilating surgery for the nerve and ligation of the stalk connecting the ganglion to the proximal tibiofibular articulation. A review of the controversial pathogenesis of the intra- and extraneural ganglia is exposed, and the anatomy, the diagnosis, the surgical treatment and the prognosis is discussed in light of relevant literature.