Blood flow in the femora, tibiac, and second metatarsals distal to a femoral arteriovenous fistula in immature dogs functioning from one hour to twenty-five weeks was studied by means of short-term (ten minutes) clearance by the skeleton of Sr85 and Ca47 from the blood. It was found that plasma flow per gram of bone decreased in these bones on the side of the fistula one hours after creation of the fistula. Thereafter, the flow in the femora on the side of the fistula increased to above normal while in the tibiae and second metatarsals it increased but remained below normal when calculated on the basis of bone weight. There was no consistent relationship between change in bone plasma flow and change in bone weight.