Glycolysis reactions of waste polyethylene terephthalate (PET) flakes obtained from post-consumer water bottles were carried out at 220-250 degrees C using diethylene glycol, dipropylene glycol and triethylene glycol, and molar ratios of PET/glycol in the glycolysis reactions were chosen to be 1/3. The obtained glycolysis products were used in the synthesis of medium-oil acrylic- modified water-reducible alkyd resins. Acrylic modification was carried out using methacrylic acid-maleic acid copolymer synthesized in our laboratory. The structure of the acrylic copolymer was investigated with FTIR analysis. Films of the modified alkyd resins were prepared and their physical and chemical surface coating properties were investigated. When surface coating test results were evaluated, it was observed that waste PET had no adverse effect on these properties of acrylic-modified water-reducible alkyd resins. Then, two water-based paints were prepared using PET-based acrylic-modified water-reducible alkyd resin and reference acrylic-modified water-reducible alkyd resin as binder. Wet paint properties and physical/chemical dry film properties of paints were determined. When the physical surface coating test results were evaluated, no difference was observed between the properties of both paints. If we evaluate the results of chemical surface coating properties, the hot water and alkali resistance of waste PET-based paint was considerably higher than the reference resin.