The activity coefficient data were reported for (water + potassium chloride + DL-valine) at T = 298.15 K and (water + sodium chloride + L-valine) at T = 308.15 K. The measurements were performed in an electrochemical cell using ion-selective electrodes. The maximum concentrations of the electrolytes and the amino acids studied were 1.0 molality and 0.4 molality. respectively. The results of the activity coefficients of DL-valine are compared with the activity coefficients of DL-valine in (water + sodium chloride + DL-valine) system obtained from the previous study. The results show that the presence of an electrolyte and the nature of its cation have a significant effect on the activity coefficient of DL-valine in aqueous electrolyte solutions.