An experimental study was performed to determine the extent of shear-induced augmentation of oxygen diffusion in blood. The results were obtained using whole human blood in laminar flow through semipermeable membrane tubes. Transfer enchancement in whole blood was found to be dependent on the fluid shear rate and the hemoglobin saturation level. Very little agumentation was observed in saturated blood for shear rates up to 2500 s−1. However, with partially unsaturated blood, oxygen transfer was increased up to 250 percent at the higher shear rates. The implications for modeling oxygen transfer in blood are discussed.