In this work, the results relating to the mean activity coefficient measurements for NiCl2 in the NiCl2+glucose+water system using the potentiometric method are reported. The potentiometric measurements were performed on the galvanic cell of the type: Ag vertical bar AgCl vertical bar NiCl2 (m), glucose (w%), H2O (1 - w)% vertical bar Ni-ISE, in various mixed solvent systems containing 0%, 10%, 20%, 30% and 40% mass fraction of glucose over ionic strength ranging from 0.0012 to 5.000 kg mol(-1). The Pitzer ion-interaction model was used for the experimental data correlation and calculation of thermodynamic properties. The Pitzer ion-interaction parameters (beta((0)), beta((1)) and C-phi) for each of the mass fractions of glucose were determined. Then, the obtained Pitzer parameters were used for the evaluation of the other thermodynamic properties such as of osmotic coefficients (phi) and excess Gibbs free energy for the investigated system.