An insulin signaling pathway microarray was used to evaluate the gene expression profiling of the insulin signaling pathway in the skeletal muscle of streptozotocin-induced diabetic, NaVO₃-treated diabetic and insulin-treated diabetic rats for the investigation of the effect of vanadium and insulin on the insulin signaling pathway. Of 96 genes surveyed, transcriptional patterns of 19 genes (20%) showed alterations in diabetic rats compared with controls. Although most of these changed gene expressions were improved after treatment with NaVO₃ (14, 74%) and insulin (16, 84%), NaVO₃ and insulin treatment resulted in the alteration of 20 and 12 additional gene transcripts compared no treatment. We found that both NaVO₃ and insulin treatment achieved a desirable glucose level and most of the alterative gene transcripts in diabetic rats were normalized with NaVO₃ and insulin treatment. Comparison of the gene expression profiling indicates that there is a significant difference between the NaVO₃-treated group and the insulin-treated group. The present study demonstrated for the first time that several candidate genes of the insulin signaling pathway are involved in the effect of vanadium treatment on hyperglycemia. This study opens the way for more focused investigations that may identify the genes responsible for diabetes and vanadium treatment in the global insulin signaling pathway.