We investigated the progression of carotid atherosclerosis in a population-based sample of 100 Eastern Finnish men aged 42, 48, 54 or 60 years. A high-resolution B-mode ultrasonographic examination was repeated after a follow-up of 24 months for each subject. The intimal-medial thickness (IMT) in the common carotid artery increased by -0.06 mm to 0.90 mm (mean 0.12 mm, SD 0.20 mm). Age (standardised partial coefficient, beta = 0.325, P = 0.0003), serum LDL cholesterol concentration (beta = 0.229, P = 0.0011), pack-years of smoking (beta = 0.274, P = 0.0023), blood leukocyte count (beta = 0.201, P = 0.0239), and platelet aggregability (beta = 0.165, P = 0.0646), measured at baseline, were the strongest predictors of atherosclerosis progression. Neither hypertension, current blood pressure level, serum HDL cholesterol nor serum HDL2 cholesterol concentration at the baseline examination had any association with the change of IMT over 2 yrs.