The main purpose of this work is to study the removal of nitrate from water using electrodialysis (ED). The influence of the flow rates, electrolyte concentration, and coexisting anions on ED efficiency was studied. Response surface methodology (RSM) was applied in the development of statistical analysis, modeling, and interpretation of the resultant treatment data of nitrate removal by ED. From the analysis of variance, the flow rate and the electrolyte concentrations were found to be the most significant effect on nitrate removal.