Toward the end of the last century a better knowledge of cardiovascular (CV) risk factors and their associations led investigators to propose the existence of a unique pathophysiological condition called "metabolic" or "insulin resistance syndrome". Among all, insulin-resistance and compensatory hyperinsulinemia are considered its most important treatment targets. Different definitions have been provided by World Health Organization (WHO) and by The Third Report of The National Cholesterol Education Program's Adult Treatment Panel (NCEP-ATP III). In particular, abdominal obesity, hypertension, low HDL cholesterol and hyperglicemia are the most common items used for its definition. The presence of MetS is effective in predicting the future risk of diabetes and coronaropathies. The evidence of a higher CV risk rate among different rheumatic inflammatory diseases has recently been associated with high prevalence of MetS in some cases. Rheumatoid or psoriatic arthritis have the large series among arthritis, whereas systemic lupus erythematosus among connective tissue disorders. This review analyses all most important studies about the evidence of MetS in rheumatic patients and the main clinical and prognostic significance of this relation.