Heavy metal pollution has become one of the most serious environmental problems today. Heavy metals treatment is of the special concern due to their recalcitrance and persistence in the environment. In this study, four metals (Cr, Cu, Ni, and Zn) found in an industrial wastewater treatment plant in Sfax (South-Eastern Tunisia) were monitored for 10 months in 2012. Metal influent and effluent concentrations of wastewater flocculation process measured via 24-h composite samples were used to determine removal efficiencies. Average influent concentrations varied between 16 ± 13.03 mg/L (Zn) and 167.21 ± 120.06 mg/L (Cr). The flocculation process yielded high removal efficiencies of the studied metals (93%). Treated wastewaters quality was evaluated according to Tunisian standards for emission into the sewerage system. It was determined that effluent quality in terms of biological oxygen demand, suspending solid, chemical oxygen demand, pH, Cu, and Zn levels were in agreement with standards, but Cr and Ni residual loads were still above the values required by quality criteria.