Bile flow studies were performed in 3 groups of awake rhesus monkeys. In the first group, the increase in bile flow stimulated by secretin was not accompanied by an increase in erythritol 14C clearance. Resection of the gastric antrum and small intestine in the second group resulted in stable bile flow at fixed bile salt secretion rates. Linear regression lines for bile flow versus bile salt secretion rate and erythritol 14C clearance versus bile salt secretion rate were parallel, and the Y axis intercept for the latter was consistently higher for the former. It is concluded that erythritol 14C clearance equals canalicular flow, and ductular reabsorption is constant at all bile salt secretion rates in this species. Bile flow was studied during fasting and feeding, over 6 days, in the third group. A model incorporating 4 bile flow components was developed and tested by multivariate regression analysis. The data fit the model quite well, explaining > 90% of the variation in bile flow. A method of measuring the contribution to bile flow of each of the 4 components is provided.