Cytosolic free calcium and intracellular calcium stores were measured in neutrophils by trapping intracellularly the fluorescent calcium indicator Quin-2. Ten patients with untreated essential hypertension were compared to 10- age and sex-matched normotensive subjects. Intracellular calcium concentration and calcium stores did not differ in the two groups. No significant relationship was found between blood pressure and the calcium parameters. These results suggest that essential hypertension is not associated with a generalized cellular alteration in calcium handling.