In this study, the removal of turbidity from drinking water by electrocoagulation (EC) and chemical coagulation (CC) processes was investigated. Turbidity removal efficiencies to measure of the treatment removal were taken into consideration. Two electrode materials aluminum and iron were used in EC process were connected as monopolar parallel; the effects of the type of electrode, initial pH, current density and electrolysis time on the removal of turbidity were investigated. The optimum operational conditions for each of electrodes materials were found to be pH 7.9, current density 10 A/m(2) and electrolysis time 3 min. In these conditions; turbidity removal efficiencies and operational costs were 99 %, 96 % and 0.0234 $/m(3), 0.0247 $/m(3) respectively. Type of coagulant, initial pH and coagulant dosage were investigated in CC process. Also, in both of EC and CC processes operational cots were calculated and compared. Three different coagulants (Al-2(SO4)(3).18H(2)O, FeSO4.7H(2)O, FeCl3.6H(2)O) which were respectively used in coagulation process; optimum operational conditions were found to be pH 7.9 and 20 mgMe(+)/L. For each of coagulants turbidity removal efficiencies and operational costs were 94.5 %, 93.9 %, 95.3 % and 0.0987 $/m(3), 0.0397 $/m(3), 0.0328 $/m(3), respectively. Also, in the optimum conditions of processes; filtration was applied to drinking water samples and filtrations of process exits were investigated. As a result, EC process is more effective in turbidity removal efficiency and operational cost than CC process.