The effect of hemorrhagic hypotension and resuscitation on regional blood flow was studied in the Macaca fascicularis monkey. The majority of the splanchnic vasculature demonstrated a profound decrease in flow. Following fluid expansion and correction of acidosis, flow increased in these circulations but did not reach control values. Exceptions were the small bowel flow which fell only moderately and hepatic arterial flow which did not significantly change. Both coronary and adrenal circulations maintained flow during the shock and resuscitation periods, whereas brain and kidney blood flows fell significantly without recovery. There was a significant rise in serum glucose, lactate, and pyruvate during shock, with an increase in the lactate/pyruvate ratio. Following resuscitation, the ratio decreased, implying a return toward aerobic metabolism.