Introduction. Intraneural synovial cyst is a rare pathological condition, which can be symptomatic due to the compression of the neighboring structures, including the peroneal nerve. The purpose of this publication is to present a clinical case of intraneural ganglion of the peroneal nerve with a critical analysis of diagnostic and tactical errors in diagnosis and treatment tactics, and literature review. We present a clinical case of a patient with an intraneural cyst of the peroneal nerve, who had 3 surgical interventions over a period of 1.5 years from the age of 13 years, followed by recurrences without restoration of muscle function. The case demonstrates underestimation of the pathogenesis of the described condition - the presence of a communicant nerve between the proximal tibiofibular joint and the peroneal nerve and proximal tibiofemoral joint as the source of synovial effusion. Awareness in relation to this pathology will improve the efficiency of diagnosis. Interdisciplinary approach of pediatric neurologists, orthopedists, neurophysiologists and radiologists can shorten the diagnostic stage and enable the earliest and most effective surgical treatment to avoid irreversible consequences due to prolonged muscle denervation.