We describe pulsed-field gel electrophoresis (PFGE) analysis of 10 unrelated Italian families and seven isolated cases with hereditary neuropathy with liability to pressure palsies (HNPP). Our sample includes patients with different clinical features, varying from classical liability to pressure palsies to ingravescent polyneuropathy. The frequency and the uniformity in size of the 17p11.2 deletion was evaluated by using cosH1 probe from the Charcot-Marie-Tooth neuropathy type 1A (CMT1A)-REP region. The presence of the deletion was demonstrated in all our patients; furthermore, the deletion was of identical size, although our patients had different clinical features. Molecular analysis of the 17p11.2 region by PFGE method proved to be a reliable and non-invasive method of diagnosis in HNPP cases both familial and isolated.