Insulin stimulates microvascular recruitment in skeletal muscle and this vascular action augments muscle glucose disposal by ~40%. The aim of the current study was to determine the contribution of local nitric oxide synthase (NOS) to the vascular actions of insulin in muscle. Hooded Wistar rats were infused with the NOS inhibitor N-L-nitro-arginine-methyl ester (L-NAME, 10µM) retrogradely via the epigastric artery into one leg during a systemic hyperinsulinemic euglycaemic clamp (3mU.min-1.kg-1x 60 min) or saline infusion. Femoral artery blood flow, microvascular blood flow (assessed from 1-methyl xanthine metabolism) and muscle glucose uptake (2-deoxyglucose uptake) was measured in both legs. Local L-NAME infusion did not have any systemic actions on blood pressure or heart rate. Local L-NAME blocked insulin-stimulated changes in femoral artery blood flow (84%, P<0.05) and microvascular recruitment (98%, P<0.05), and partially blocked insulin-mediated glucose uptake in muscle (reduced by 34%, P< 0.05). L-NAME alone did not have any metabolic effects in the hindleg. We conclude that insulin-mediated microvascular recruitment is dependent on local activation of NOS in muscle, and that this action is important for insulin's metabolic actions.