A patient with chronic renal disease due to primary hyperoxaluria developed a rapidly progressing motor neuropathy with marked impairment of nerve conduction. Pathological studies demonstrated the presence of both axonal degeneration and segmental demyelination, together with the presence of oxalate crystals within axons. It is suggested that the development of peripheral neuropathy complicating hyperoxaluria is a consequence of the increased life-span mad possible by haemodialysis.