The Metabolic or Insulin Resistance Syndrome is a cluster of cardiovascular risk factors, such as type 2 diabetes mellitus, hypertension, central obesity, dyslipidaemia, and other disorders, which have been proposed to be secondary to insulin resistance. A number of possible mechanisms linking insulin resistance and compensatory hyperinsulinemia with hypertension have been described, such as renal sodium reabsorption enhancement, sympathetic nervous system activation, or blunted insulin-mediated vasodilatation due to endothelial dysfunction. PPARγ agonists or thiazolidine-diones (TZDs) are a class of oral antihyperglycemic agents that act through improvement of insulin sensitivity. Apart from their action on glycemic control, in several studies TZDs have been also reported to exert beneficial effects on other parameters of the metabolic syndrome. This review summarizes the literature data on the effect of troglitazone, pioglitazone and rosiglitazone on blood pressure (BP), which derive from animal and human studies that were either specifically designed to determine the effect of TZDs on BP or just examined BP levels among other parameters. In addition, it presents in vitro and in vivo evidence about various TZDs actions on the cardiovascular system that could positively influence BP, representing therefore possible mechanisms of this BP amelioration.