We present a 10-year-old female diagnosed having hereditary neuropathy with liability to pressure palsies (HNPP). She had suffered from acute, recurrent monoplegic episodes affecting both the sciatic nerves and the left brachial plexus since the age of 7 years. The paresis seemed to be triggered by hiking and athletic training. Electrophysiological studies showed a conduction block in the proximal portions of affected nerves. The FISH method disclosed a deletion of the peripheral myelin protein 22 gene. This school child having HNPP is considered to be susceptible to the influence of abundant physical training, rather than minor trauma or compression at sites of entrapment of peripheral nerves.