The relationship between flow motion and tissue oxygenation was investigated during hemorrhage/retransfusion with and without dopamine in 14 pigs. During 45% bleed, jejunal microvascular hemoglobin O₂ saturation (HBjO₂) and mucosal tissue PO₂ (PO_2muc) were recorded in seven control and seven dopamine-treated animals. Mean arterial pressure and systemic O₂ delivery decreased during hemorrhage and returned to baseline after retransfusion. Hemorrhage decreased PO_2muc from 33 ± 2.8 to 13 ± 1.6 mmHg and HBjO₂ from 53 ± 4.9% to 32 ± 3.9%, respectively, in control animals. During reperfusion, PO_2muc and HBjO₂ remained low. Dopamine increased PO_2muc from 28 ± 4.3 to 45 ± 4.6 mmHg and HBjO₂ from 54 ± 5.7% to 69 ± 1.5% and attenuated the decrease in PO_2muc and HBjO₂ during hemorrhage. After retransfusion, dopamine restored PO_2muc and HBjO₂ to baseline. Control animals developed rhythmic HBjO₂ oscillations with increasing amplitude (frequency, 4.5 to 7.6 cycles/min) and showed an inverse relationship between PO_2muc and HBjO₂ oscillation amplitude. Dopamine prevented regular flow motion. The association between decreased PO_2muc and increased oscillations in HBjO₂ after normalization of systemic hemodynamics and O₂ transport in control animals suggests a cause-and-effect relationship between low tissue PO₂ and flow motion activity within the jejunal microcirculation.