This paper investigated the possibility of using the natural zeolite clinoptilolite of particle size 0.09 - 0.56 mm as filler in permeable reactive barriers for the remediation of mercury contaminated environment. The experiments were carried out on a sample of contaminated soil with a particle size of 0.075 mm and with mercury content of 1347 mg/kg, from the surrounding of Idrija mine in Slovenia, the second largest mercury mine in the world. Leaching of mercury from soil was carried out in ultrapure water of initial pH o values of 4.11; 5.09 and 6.04 without and with addition of natural zeolite clinoptilolite, at room temperature, with stirring at ≈ 800 rpm for 24 h. The process was monitored by measuring the pH value, electrical conductivity, and concentration of total leached mercury at defined time intervals within 24 h. Concentration of the total leached mercury in suspensions without the presence of natural zeolite ranged from 12.8 to 42.2 µg/L, far above the maximum permissible concentration of mercury of 1 µg/L in waters for human consumption. A significantly lower concentration of total mercury (from 1.9 to 20.3 µg/L) was leached in the presence of natural zeolite for all examined pH o values, indicating the zeolite sorption of ionic mercury species and their retention in the zeolite structure. The removal efficiency α of total leached mercury on natural zeolite at given experimental conditions was from 33.0 to 90.5%, and the best removal was achieved at the lowest initial pH o value of 4.11. According to the obtained results, natural zeolite could be used in the remediation of mercury contaminated environment, but it is necessary to carry out several stages of removal to reduce the concentration of total mercury below the maximum permissible level in water for human consumption.