The objective of this study was to investigate the effect of coagulant addition on the filter performance and effluent quality during media filtration of surface water contaminated with diesel oil. A pilot scale multi-media filter system was operated under constant head conditions and at a constant loading rate of 30 L/min. The tests were conducted with and without coagulant addition prior to filtration of the surface water contaminated with diesel oil. Each filtration run was continued until the pressure drop increased to 0.7 bar. The source water with a turbidity of 10-15 NTU was prepared by mixing bentonite clay with tap water. The effect of coagulant addition on the performance of a multi-media filter for treatment of diesel oil contaminated source water was evaluated based on pressure change, filter run time before the filter clogged, and turbidity removal. The coagulant addition significantly improved the operational time of the media filter by reducing the rate of clogging. Both turbidity and PHC removal was achieved during the runs with coagulant addition.