The aim of this study was to investigate possible abnormalities in salivary electrolytes in hypertensives treated with ace-inhibitors (ACE-I) or calcium antagonists (Ca-ANT) at low or normal sodium intake. Hypertensives treated with ACE-I (n.14) or Ca-ANT (n.22) and 13 normotensives were studied during normal or restricted Na intake. Na, K, Ca, Mg and Cl were determined in saliva samples collected by using a standardized adsorption procedure (SALIVETTE). Na intake was evaluated by determination of the 24-hr urinary Na excretion. Similar concentrations of Na, K, Ca, and Cl were found in normotensives and in hypertensives treated with ACEI or Ca-ANT both at low or normal Na diet. Magnesium in saliva appeared reduced in ACEI-treated hypertensives (0.28 +/- 0.06 mmol/l) in comparison to the similar values of normotensives (0.53 +/- 0.05) and Ca-ANT treated hypertensives (0.54 +/- 0.07). In normotensives and in treated hypertensives lowering of Na intake did not change the salivary content of Ca, Mg and Cl but produced in saliva a reduction of Na associated to a rise in K. Salivary Na/K ratio was significantly correlated with 24 hr urinary Na excretion in normotensives (r = 0.77; p < 0.05) and in hypertensives treated with ACE-I (r = 0.74; p < 0.05) or Ca-ANT (r = 0.62; p < 0.05). The low salivary magnesium in ACE-I-HT may have a role in the occasional ACEI-dependent dysgeusia. Salivary Na/K ratio may be used as a rough index of Na intake in treated hypertensives.