Immune system disturbances have been implicated in the pathogenesis of essential hypertension. The aim of this study was to determine the levels of the interleukin-1 beta and soluble interleukin-2 receptors in serum samples from 114 hypertensive patients before any drug therapy because there are no well-established data regarding these immunologic mediators in essential hypertension. We found increased levels of interleukin-1 beta in 59.6% of patients, while soluble interleukin-2 receptors were not detected. The interleukin-1 beta levels were significantly higher in patients than in healthy controls (P = 0.0001). We conclude that patients with essential hypertension have high levels of interleukin-1 beta but not indicators of cellular immune activation in their sera. Further studies are in progress in order to confirm, explain and assess the clinical utility of the above findings.