To study the effect of interstitial edema on tissue oxygen transport, we infused buffered isotonic saline solution at a rate of 200 ml/kg/hr into mongrel dogs for two hours, measuring oxygen delivery and consumption in a skinned, innervated hindlimb. Hematocrit dropped gradually to 10.8 +/- 3.9%. Muscle water content increased 13% (P less than 0.05). However, oxygen consumption did not change significantly from control of 0.228 +/- 0.029 ml/min/100 gm. Femoral venous oxygen tension fell from control of 62.6 +/- 2.6 mm Hg to 31.4 +/- 2.3 mm Hg. Mean arterial flow increased to nearly twice the control level of 12.5 +/- 1.1 ml/min/100 gm and fell gradually, with the sustained 50% drop in vascular resistance largely explained by expected decreases in blood viscosity. We conclude that interstitial edema did not cause a significant defect in canine skeletal muscle oxygen utilization.