In this study we assessed the magnitude of the erratic deviations in the radial position of red blood cells in the laminar flow regime of the arterioles in the hamster window preparation and the intraluminal pO₂ profile, to determine if this variability affects the intraluminal distribution of oxygen in conditions of normal hematocrit and hemodilution. A gated image intensifier was used to visualize fluorescently labeled red blood cells in tracer quantities, and obtain multiple measurements of red blood cell radial and longitudinal positions at time intervals of the order 5 ms within single arterioles (diameter range 40 - 95 µm). Red blood cells in the velocity range of 0.3 - 14 mm/s exhibit a mean coefficient of variation of velocity of 16.9 ± 10.5% and a SD of the radial position of 1.98 ± 0.98 µm. Both quantities were inversely related to hematocrit, and the former was significantly lowered by hemodilution. Our experimental results presented very similar values and shape as compared to the intraluminal oxygen profile derived theoretically for normal hematocrit, suggesting that shear augmented diffusion due to the measured radial displacement of red blood cells did not significantly affect oxygen diffusion from blood into the arteriolar vessel wall. PO₂ profiles in the arterioles assumed an increasingly parabolic configuration with increasing levels of hemodilution.