Up to 50% of people with diabetes have some degree of peripheral neuropathy, putting them at increased risk of foot ulceration, and up to 15% of all foot ulcers result in an amputation. This article describes a prevalence and incidence-based cost-of-illness study undertaken to qualify the annual cost to the NHS of diabetic peripheral neuropathy among people with type 1 and type 2 diabetes in the UK. The robustness of the cost estimates was assessed by performing sensitivity analyses in which the rates of complications were varied.