Crude extracts prepared from the heartwood of Taxus baccata L. were evaluated for their antiplatelet and vasorelaxing effect. The ethanol extract of the heartwood of T baccata (1) and their fractions, CHCl3 (2) and CHCl3 nonsoluble extract (3) were preincubated with platelets, and then thrombin, arachidonic acid (AA), collagen or platelet-activating factor (PAF) was added for testing antiplatelet activity. In other set of experiments, all extracts were tested on high potassium or norepinephrine (NE) depolarized isolated rat thoracic aorta for investigating the vasorelaxing effect. All tested extracts showed a significant inhibitory effect on platelet aggregation induced by AA, collagen and PAF at a concentration of 400 mug/ml, but not thrombin. However, not all extracts relaxed NE-induced vasocontraction, extracts 1 and 2 showed a weak inhibitor effect on high potassium depolarized smooth muscle. To the best of our knowledge, this is the first report on antiplatelet activity and vasorelaxing effect of the heartwood of T baccata.