The main objective of this study is to investigate the effect of coagulants and nano-coagulants in different concentrations to reduce the TSS of industrial wastewater using the Taguchi statistical method. Two chemicals, iron chloride and aluminum sulfate, and two nanoparticles of iron oxide and alumina, were used as coagulants within the wastewater flocculation process at Beshel industrial complex. A L16 orthogonal array with the four factors of control at four levels each and two interactions was employed for optimization of coagulants and nano-coagulants concentration to reduce total suspended solids (TSS) in industrial wastewater. The concentration of iron chloride 1.5 g/l, concentration of iron oxide nanoparticles 1.5 g/l, concentration of aluminum sulfate 1.5 g/l and concentration of alumina nanoparticles 1.5 g/l was the optimal conditions to reduce the TSS of industrial wastewater.