Three cases of neurogenic muscular hypertrophy are reported. First case presented a hypertrophy of one calf following S1 radiculopathy; the second had a hypertrophy of tibialis anterior muscle, five years after a compressive injury of the common peroneal nerve. The third case is a global hypertrophy of leg muscles after intensive care or legionella neuropathy. Previous cases of the literature are reviewed and the various pathophysiological hypothesis are considered. Among these hypothesis, the role of abnormal electrophysiological activities in most previous cases, as well as in ours (namely complex repetitive discharges and fasciculations), seems the most consistent.