BACKGROUND: The aim of the study was to evaluate the relative importance of the determinants of the metabolic syndrome in a sample with metabolic syndrome from the Greek population. METHODS: A random sample of 824 male (56 ± 11 years) and 1,199 female (58 ± 10 years) subjects with metabolic syndrome [National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III)], but without diabetes mellitus or established cardiovascular disease, was selected from all over Greece. Principal components analysis (PCA) was applied to evaluate the interrelationships between the inherent characteristics of the metabolic syndrome. RESULTS: Among the participants, 87.6% had elevated blood pressure levels, 79.9% had hypertriglyceridaemia, 62.6% had low high-density lipoprotein cholesterol (HDL-C) levels, 71.4% had impaired fasting glucose (FG), and 91.5% had abdominal obesity. The most common combination was elevated blood pressure levels, abdominal obesity, impaired fasting glucose (FG), and hypertriglyceridemia (14.2%). PCA revealed three main components that explained 68.4% of the total variation. The first one was heavily loaded by blood pressure (28.6% of the total variation explained), followed by a component characterized by lipid variables (21.7%) and a component characterized by FG and waist circumference measurements (18.1% explained variation). CONCLUSIONS: The most dominant characteristic of metabolic syndrome participants from a Mediterranean country (Greece) was elevated blood pressure levels, which were present in all eight of the most common combinations of metabolic syndrome components, rendering the "hypertensive aspect" of metabolic syndrome the most common one. Because a significant proportion of hypertensive subjects with metabolic syndrome receive no treatment, or are poorly controlled, targeting blood pressure levels in the general population may assist in better preventing metabolic syndrome and its complications.