The aim of this study is to investigate the performance of solar photo-Fenton process (H2O2/Fe2+/Solar) to treat petroleum wastewater from Sohar oil Refinery, Oman. The effect of operating conditions such as pH, reaction time, Fenton ratio, and Fenton reagent concentrations are investigated. The obtained optimum conditions include H2O2 dosage (1 g L-1), Fe+2 dosage (0.08 g L-1), pH (3) and reaction time (180 min). TOC and COD removal rates are 64 % and 78 %, respectively. However, the photolytic process was less efficient in the petroleum wastewater treatment, achieving an 11.5% and 9% of COD and TOC removals, respectively. The solar photo-Fenton process has well efficient for petroleum wastewater treatment in the acidic conditions and more economic by free energy.