Blood fluoride (16984488) concentrations following fluoride exposure were studied in rabbits. Ten male rabbits were exposed to hydrogen-fluoride (7664393) for 1 to 5 days at a concentration of approximately 29 milligrams per cubic meter. Blood specimens were obtained by heart puncture and analyzed for fluoride content. Post exposure samples were examined for 6 days. Fluoride concentrations varied widely among rabbits. They were generally 5 times normal following a 1 day exposure but increased only slightly even after continued exposure. Abnormally high concentrations of fluoride persisted for 3 days following exposure. Six days after exposure, fluoride concentrations had returned to normal values. The authors conclude that the capacity for removal of fluoride from the blood through excretion and deposition in bone is apparently not affected by the fluoride concentration employed. Differences in fluoride concentrations among rabbits are attributed to individual differences in fluoride excretion capacity. In future investigations, the dog may offer several advantages over the rabbit as an experimental animal.