THREE DIFFERENT newly isolated marine fungi were subjected to 18S rRNA gene partial sequence analysis. The resulting sequences showed that the isolates belong to Fusarium solani, Trichoderma viride and Aspergillus niger. The isolates have the ability to utilize some petroleum hydrocarbons such as hexane, motor oil, and diesel oil. The tested fungi could grow up to 7 days, especially on medium supported with diesel oil. Although all of the tested fungi have the ability to utilize the increased concentrations of diesel oil, Fusarium solani EH has the highest ability, growing at a concentration of 4 ml/l. Static and shaking incubation conditions of Fusarium solani EH with 7.2 mg/100ml diesel oil as a sole carbon source, showed a significant decrease in the hydrocarbon concentration (90.28% and 93.05%, respectively) within 7 days. Results of this study may provide a help in petroleum hydrocarbon spill clean-up.