The winery industry generates large volumes of wastewater which can be toxic if released to the environment without proper treatment. The aim of this work was to treat two winery wastewaters (from red and white wine production) by Fenton based processes. With application of the best operational conditions pH = 3.0, [ferrocene] = [FeSO₄•7H₂O] = 0.50 g/L, [H₂O₂] = 155 mM, temperature = 298 K, radiation UV (254 nm), to the treatment of a red WW, it was achieved a chemical oxygen demand (COD) removal of 98.9 and 84.5%, respectively, for homogeneous and heterogeneous photo-Fenton. The same conditions were applied in the treatment of a white WW and it was achieved a 98.9 and 84.5% COD removal. Based in the results it is concluded that Fenton based processes are effective in WW treatment.