We present clinical and laboratory data from a patient with Waardenburg's syndrome type II comprising iris heterochromia and deafness, complicated by Hirschsprung's disease--a known association--and an unusual demyelinating peripheral neuropathy--a unique association. The neuropathy is characterised by excessive focal folding of myelin sheaths. It is our view that, although both disorders could represent the consequences of neural crest embryopathy, it is more likely that they are associated by chance.