Although the specific anticoagulant activity of dermatan sulphate is seventy times less than that of standard heparin, its venous antithrombotic activity, tested on a great number of experimental models, appears at gravimetric doses which are only seven fold higher. This antithrombotic activity is not correlated with the factor Xa inhibition, but is associated with thrombin generation inhibition and potentiation of heparin cofactor II. Meanwhile, others factors, still non entirely identified, i.e. like the release of endogenous tissue plasminogen activators, must probably be involved in the antithrombotic activity of dermatan sulphate. In contrast to heparin, dermatan sulphate possesses hemorrhagic properties only at doses which are forty times higher than the antithrombotic dose. These hemorrhagic properties seem associated with an inhibition of collagen induced platelet aggregation. Finally, the pharmacokinetic profile of dermatan sulphate after intravenous injection in the rabbit, is different from that of standard heparin, and close to that of low molecular weight heparins.