A solution of human hemoglobin bound to benzene tetracarboxylate substituted dextran, whose physicochemical characteristics are defined in part I, was evaluated in vivo as a potential red blood cell substitute. Further experiments show: - the confirmation of a lack of acute toxicity in mice and guinea pigs after injection of 12.5%, 25% and 50% of the blood mass and the absence of death in rabbits having undergone three successive 25% hemorrhagic shocks in three week intervals. A plasma half-life of 9.5 +/- 0.5 hours in 70-75% hemorrhagic shocks on guinea pigs and the absence of dex-BTC-Hb in thoracic and abdominal cavities. No tissue oedema was noticed. Total hemoglobinuria did not exceed 10% of the injected hemoglobin quantity and only involved free hemoglobin. A lack of death in 70-75% hemorrhagic shocks and survival times ranging from 10 hours to 3 days in total exchange transfusions in guinea pig experiments.