The REgression GRowth Evaluation Statin Study (REGRESS) is a two year double blinded placebo controlled prospective atherosclerosis regression study, primarily investigating pravastatin treatment by means of quantitative coronary analysis in a 885 male population with coronary disease. In the REGRESS ultrasound substudy, 255 patients received five B-mode scans, which were used to do intima-media thickness (IMTI measurements of three carotid and two femoral arterial wall segments. One of the aims was to detect a difference in the change of the combined far wall lMT's between the pravastatin and the placebo group (respective baseline values: age 56.8 (8.1) and 55,2 (7,7); LDL-chol. 4.36 (0.80) and 4.33 (0.79) mmol/l; mean far wall IMT 0.88 (0.34) and 0.91 (0.33)mm, p = 0.41). Pravastatin treatment caused a stable decrease in LDL-chol. of 1.4(0.8) mmol/l (p < 0.001) after two months, Multivariate repeated measurements variance analysis showed a statistically significant effect of pravastatin (p < 0.001) on the mean combined far wall lMT. The largest effect was observed in the common femoral artery: 0.09 mm. (SE0.05) decrease in the pravastatin, and 0 13 mm (SE 0.05) increase in IMT in the placebo group. Pravastatin induced a decrease in far wall IMT.