To determine whether arterialized venous blood obtained from a foot vein could be substituted for arterialized venous blood obtained from a hand vein during studies using the glucose clamp technique, we simultaneously measured glucose concentrations and pO2 in blood samples obtained from the heated hands and feet of five normal volunteers during the euglycemic and hyperglycemic steps of a hyperinsulinemic clamp. Plasma glucose concentrations were found to be virtually identical in arterialized venous blood drawn from the hand and the foot under both euglycemic and hyperglycemic conditions. The correlation between these values was significant (R2 = .99, P < .001). pO2 measurements in blood drawn from the heated hand or foot were not statistically different. We conclude that the glucose concentration measured in arterialized venous blood drawn from the foot is equivalent to the concentration in arterialized venous blood drawn from the hand. These observations will allow investigators to study in vivo glucose metabolism in individuals with poor venous access in the upper extremities and to use protocols that make the arms of the subject inaccessible for blood sampling during the study.