Anamnestic variables: All ultrasonic variables have been investigated. Analyses have been performed without and with adjustment for confounders. Results: Ultrasonic variables are significantly greater in men than in women and greater in north than in south Europe; Age, Systolic blood pressure (SBP) and pulse pressure are strong determinants of ultrasonic variables; Diastolic Blood pressure (DBP) is a determinant of bulb-IMTmean, ICA-IMTmean and IMTmean; Height, Hip, Waist/Hip ratio and heart-rate are not independent determinants of carotid IMT; Weight is a determinant of CC-IMTmean and ICA-IMTmean; BMI and Waist are determinants of CC-IMTmean; Sonographers and readers are associated to IMT, thus they have been considered as confounders in all the analyses; Smoking status, Pack-years, smoke duration, N° of cigarettes smoked per day and Years elapsed since smoking cessation (YEARSQU) are strong and independent determinants of carotid IMT; AGE-smoking-start is not a determinant of carotid IMT. All smoking results were confirmed also by trend analyses. Nutrition: Wine, beer and spirit are not associated with carotid IMTs; whereas the total amount of alcohol consumed (irrespective of derived from wine, beer or spirit) is a determinant of bulb-IMTmax, IMTmax and bulb-IMTmean; Meat, fish, Eggs, Fruit, Milk and tea consumption are not associated to carotid IMTs; Coffee consumption is an independent determinant of ICA-IMTmax, and IMTmean; Years of diet is an independent determinant of CC-IMTmax, and CC-IMTmean. Blood count: Leucocytes are strong determinants of carotid IMT, whereas Monocyte, Erythrocytes, Haemoglobin, Haematocrit, MCH, MCHC, MCV, Platelets, Neutrophils, Eosinophils and Basophils are not; HDL-C is an independent determinant of CC-IMTmean, ICA-IMTmean and IMTmean; LDL-C is an independent determinant of ICA-IMTmean and IMTmean; Creatinine is an independent determinant of ICA-IMTmax, IMTmax and IMTmean-max.; After adjustment for confounders C Reactive Protein is an independent determinant of almost all ultrasonic variables. Blood glucose, Total Cholesterol, Triglycerides and Uric acid are not independent determinants of carotid atherosclerosis. Physical activity: In the whole group Physical Activity is not an independent determinant of carotid atherosclerosis. Before the adjustment for confounders the relationship between Physical Activity and IMTs was surprisingly positive (the higher the physical activity the higher the atherosclerosis). This trend is probably due to an effect of confounders, in fact, after data adjustment for confounders, even if not significant, the relationship follow the expected direction. Physical activity stratified by center: In the Milan group the analyses adjusted for age, gender, sonographer, reader and smoking habits show an association between Physical Activity and IMTmax (not confirmed in the analyses for trend) and for ICA-IMTmean (just in the analyses for trends); Physical Activity was also associated with bulb-IMT (both mean and max) in the group of Kuopio (CR3) and with CC-IMTmax and bulb-IMTmean in the group of Perugia (CR6); No association was found when the second group of Kuopio (CR2), or the groups of Stockholm (CR4), Groeningen (CR5) and Paris (CR7) were considered. Carotid IMT and personal history of disease: The status of Asthma, Respiratory Diseases, Cardiac Diseases, Ulcer, Gastrointestinal Diseases, Gout, Endocrine/Metabolic-diseases, Renal disease, Genital/Urinary disease, Ocular/Ophthalmic diseases, Immunological diseases, Rheumatoid arthritis, Osteoartrosis, Inflammatory disease, Cutaneous disease Hypothyroidism is not an independent determinant of carotid atherosclerosis; Gallstones was associated with ICA-IMTmax and ICA-IMTmean; Tuberculosis is associated with ICA-IMTmax, CC-IMTmean and IMTmean; The status of Neurological disease is associated with IMTmax, IMTmean and IMTmean-max; The status of Hypersensitivity/Allergy is associated with CC-IMTmax and IMTmean-max. Carotid IMT and personal history of a number of diseases: Family history of cardiovascular diseases, diabetes, hemoragic stroke, hyperlipidemia, hyperuricemia and obesity is not associated to carotid IMT. In fact, although associated with several IMT variables in the unadjusted analyses, all statistical significances disappeared when analyses were adjusted for confounders. In the adjusted analyses the unique variables maintaining a statistical significance as determinants of carotid atherosclerosis were: Family history of cerebrovascular diseases (associated with ICA-IMTmean), Family history of peripheral vascular diseases (associated with ICA-IMTmean and ICA-IMTmax) and Family history of hypertension (associated with Bulb-IMTmax, Bulb-IMTmean and IMTmax).