This study was carried out in two stages; in the first stage of the study, wastewater characterization of wastewater originating from the pistachio industry was primarily completed, and in the second stage, chemical pre-treatment studies were completed. Pistachio wastewater used in the study was obtained from a pistachio processing factory located in Gaziantep province. In chemical treatment studies, montmorillonite clay, AlCl3, Al2(SO4)3, Fe2(SO4)3 and FeCl3 were used as coagulants. As a result of chemical treatability tests, AlCl3 was determined to be the best coagulant. With AlCl3 at optimum dosage and optimum pH value, 99.6% suspended solid (SS) removal efficiency, 65.8% chemical oxygen demand (COD) removal efficiency and 85.5% total phenol (TP) removal efficiency were obtained.