The mechanisms of diabetic neuropathy (DN) development and progression are not fully understood. We examined global gene expression in the sciatic nerve (SCN) of BKS-db/db mice at 8 and 24 weeks of age to identify genetic pathways altered in peripheral nerves at early and advanced stages of DN. The sets of differentially expressed genes were analyzed to identify enriched biological functions and regulated genetic pathways. Our results suggest that carbohydrate metabolism and lipid metabolism pathways are dysregulated in the db/db SCN at 8 weeks of age. Impairment of Schwann cell-extracellular matrix interaction and axon guidance occurs early in the development of DN, while neurotrophic support, neurotransmitter transport and axonogenesis are impaired at the advanced stage of DN. Gene expression changes also suggest that oxidative stress- and inflammation-mediated nerve damage occurs by 8 weeks.