The present work aims to study the performance of a trickle bed reactor for phenol degradation in refinery wastewater by investigating the applicability of a commercial 0.5% platinum/alumina catalyst, which is used currently for desulfurization process in the North Refinery Company-Iraq. Synthetic wastewater experimentally was prepared to simulate the specification of samples taken from North Company Refinary. Results showed that initial phenol concentration had adverse effect on phenol removal. The results exhibited that the highest phenol conversion of (98.47%) was obtained over 0.5% Pt/γ-Al2O3 at the studied conditions (i.e., operating pressur 0.8 Mpa, operating temperature 1200C, LHSV 2.5 h-1, and air superficial velocity 0.25 m/s), with initial phenol concentration of 200 mg/L. The present method characterized by low residence time, the end-products are environmantally harmless no sludge production which requires further treatment