Atherosclerosis is the leading cause of cardiovascular disease worldwide, including in China. Primary prevention, through lipid-lowering, could avert development of atherosclerosis. Carotid intima-media thickness (CIMT) is a well-validated measure of atherosclerosis used in intervention studies as the primary outcome and alternative end point for cardiovascular disease events.This randomized, double-blind, placebo-controlled, multicenter, parallel-group study assessed the effects of rosuvastatin 20 mg/d compared with placebo on progression of CIMT over 104 weeks in Chinese people with subclinical atherosclerosis. The primary end point was the annualized rate of change in mean of the maximum CIMT measurements taken 7× over the study period from each of 12 carotid artery sites (near and far walls of the right and left common carotid artery, carotid bulb, and internal carotid artery). Secondary end points included CIMT changes at different artery sites and lipid-parameter changes. Safety was also assessed.Participants were randomized (1:1) to receive rosuvastatin (n=272) or placebo (n=271). Baseline characteristics were well balanced between groups. The change in mean of the maximum CIMT of the 12 carotid sites was 0.0038 mm/y (95% CI, -0.0023-0.0100) for the rosuvastatin group versus 0.0142 mm/y (95% CI, 0.0080-0.0204) for the placebo group, with a difference of -0.0103 mm/y (95% CI, -0.0191 to -0.0016; P=0.020). For the CIMT secondary end points, the results were generally consistent with the primary end point. There were clinically relevant improvements in lipid parameters with rosuvastatin. We observed an adverse-event profile consistent with the known safety profile of rosuvastatin.Rosuvastatin 20 mg/d significantly reduced the progression of CIMT over 2 years in Chinese adults with subclinical atherosclerosis and was well tolerated.URL: https://www.gov; Unique identifier: NCT02546323.