The possible pharmacological and toxicological effects of Pistacia terebinthus L. in experimentally hypercholesterolemic rabbits were investigated in this study. A total of 28 rabbits were divided into four groups, and these groups were fed diets containing standard pellets (Group 1), cholesterol (2%) (Group 11), P. terebinthus L. (11 g/kg body weight) and cholesterol (2%) (Group 111) and P. terebinthus L. (1 g/kg body weight) (Group IV) for 14 weeks. When the data were statistically evaluated over the weeks, body weight gains, showed no marked difference among the groups although liver weight was 58% higher in the cholesterol control group (P < 0.01) and 20.3% higher in P. terebinthus L. and cholesterol group than in the control group. In the comparison of the cholesterol-fed groups, Group III exhibited a marked decrease (P < 0.01) in total cholesterol and triglyceride evels and very low density lipoprotein (VLDL) and low density lipoprotein (LDL) levels by the 14th week and a 1.3-times higher (P < 0.001) high density lipoprotein (HDL) value. In the group fed cholesterol and P. terebinthus L., clotting and bleeding times increased by 13% and 12%, respectively, compored to the cholesterol control group. On account of the histopathological findings, it was confirmed that P. terebinthus L. restrained the progression of the atherosclerotic lesions in the thoracic artery and of hydropic degeneration and fatty changes in the liver. No toxic effect could be attributed to P. terebinthus L. from an investigation of the biochemical data. The results of this study show that P. terebinthus L. has a hypolipidemic effect in hypercholesterolemic rabbits.