Many controversial studies concerning relation between angiotensin converting enzyme polymorphism and renal and cardiovascular disease have been published during the last years. Most of the papers have suggested that the DD genotype plays an important negative role in the progression of some renal diseases (e.g. IgA nephropathy, diabetic nepropathy). The D allele may be an independent risk factor for development of the target organ damage in essential hypertension. The therapeutic response on inhibitors of angiotensin converting enzyme depends on insertion-deletion polymorphism. It probably also depends on the gender. The pathological mechanisms of insertion-deletion polymorphism have not yet been clearly identified.