A study was designed to investigate the chemical coagulation process for the treatment of the potato food industry wastewater of the “Chipsy factory” located at Abi‐Sier, Egypt. The chemical coagulants used in the study include alum, ferric chloride, calcium chloride, ferric sulphate and Nalco as polymer. Variable doses of these coagulants were examined to determine the optimum dose. Results obtained showed that chemical treatment (coagulation, flocculation, followed by sedimentation) was efficient to reduce the chemical oxygen demand (COD), total suspended solids (TSS) and turbidity significantly. Remarkable variation of the removal efficiency depends on the type of coagulant. Ferric chloride and ferric sulphate were more efficient than calcium chloride. Combination of Nalco with each of the studied coagulants improved the removal efficiency remarkably. Reduction of 91‐94 per cent of turbidity, 93‐97 per cent of COD, and 94‐97 per cent of the TSS was achieved with these combinations.