Azo dyes are synthetic colorants widely used in textile industry and are considered to be major contaminants in dye wastewater. Coagulation-flocculation is most preferred techniques to treat dye wastewater. A N,N-diisopropylamine-based new polymer was synthesized by polycondensation of epichlorohydrin, N,N-diisopropylamine, and ethylinediamine. The chemical and thermal properties of the polymer were investigated by FTIR, XRD, TGA, and viscosity measurements. The flocculation efficiency of the polymer was evaluated at different coagulant dose, organic load, and pH. The flocculation efficiency of this polymer was found to be higher over a pH range of 2-10 at its optimal dose of 80 mg/L. Morphological changes in the floc were studied by light and scanning electron microscopy. The zeta potential results clearly indicated that flocculation at the optimum doses is the result of charge neutralization and adsorption bridging. This study demonstrates the successful synthesis of the polymer, its excellent color removal efficiency (>98%) at lower doses, and effectiveness in dye wastewater treatment.