Metabolic syndrome (MS), a constellation of metabolic risk factors associated with development of cardiovascular diseases and Type 2 diabetes (T2D), has emerged as a public health problem of enormous proportions in developed and developing countries. We have reported previously its prevalence in several island populations of the Eastern Adriatic coast of Croatia. In spite of leading a relatively traditional life style pattern including adherence to a Mediterranean diet, the prevalence of MS in these populations is high and comparable to that in developed nations. However, data on prevalence of MS among the mainland Croatian populations is limited. Therefore, we conducted a study in an outbred population comprising of Croats, Hungarians and Serbs from the Baranja region of mainland Croatia. Although this is an ethnically heterogeneous population, the constituent groups exchange mates and therefore, are not reproductively isolated. The life style patterns are also similar. Overall prevalence of MS, assessed by the National Cholesterol Education Program (NCEP) criteria, is 40% (35% in males and 42% in females) with Body Mass Index (BMI) as the predictor of obesity and 42% (52% in males and 39% in females) with Waist Hip Ratio (WHR) as the predictor of obesity. It is likely that, in addition to genetic risk factors, a host of environmental factors that include dietary habits and relatively urban life style in a modernized society have influenced the levels of the constituent metabolic traits leading to an increased prevalence of MS.