A blood flow gradient exists in the small intestine of the dog when it is studied under basal conditions of anesthesia. Flow is highest in the duodenum and jejunum, and diminishes progressively in the jejuno-ileum and distal ileum. In the distal ileum the mean flow is only 65% of that in the duodenum or jejunum. This gradient was observed whether or not the abdomen had been opened prior to the measurement.