Two cases of n-hexane polyneuropathy due to glue sniffing were reported and the clinical features, laboratory data and sural nerve biopsy findings were discussed. Case 1 was a 31-year-old man and case 2 was a 24-year-old man. Both of them developed motor dominant polyneuropathy subacutely after inhalating Bond G10 for about 3 months. Their weakness deteriorated further for about 3 months even after discontinuing Bond G10 inhalation and they became almost confined to wheel chairs. Thereafter, however, they started to recover fairly rapidly. Gas chromatographic analysis of Bond G10 revealed that it contains 47.7% of n-hexane and 21.8% of toluene. Almost all reported cases of glue sniffer's neuropathy were motor dominant type, but those of n-hexane polyneuropathy of factory workers were sensory or sensorimotor neuropathy. Therefore our cases are thought to be typical of glue sniffer's neuropathies. Sural nerve biopsies were done in both patients, and examinations of photomicroscope, teased method and electronmicroscope were performed. From our photomicroscopic examinations we found only mild changes such as reduction of number of myelinated fibers, and from our electronmicroscopic examinations we noted marked accumulation of neurofilaments and loss of neurotubules in swelled axons. Some axons were normal in appearance by photomicroscopic examination, but the same axons under electronmicroscopic examination further revealed that neurotubules were oppressed by accumulation of neurofilaments to the margin of an axon. These findings seem to indicate the pathological processes of axonal swellings.(ABSTRACT TRUNCATED AT 250 WORDS)