The authors discuss a reported case of primary aldosteronism, which is relatively uncommon within hypertensive population. The diagnosis of primary aldosteronism must be suggested by the presence of the association of arterial hypertension and hypokaliemia, which nevertheless is not pathognomonic. It is emphasized the significance of the detection of this syndrome on account of the correction following surgical removal of the adenoma of the adrenal cortex. Two attacks of paroxismal hypertension, which are atypical in primary aldosteronism, had been observed in the reported case; however, apart from these exceptions, arterial hypertension has resulted generally constant and of moderate degree, as well as the majority of the others descriptions. The personal experience confirms the need to determine plasma levels of renin and aldosterone before the therapeutic or diagnostic use of spironolactone.