Yeast isolated from Cochin Backwaters were screened for their ability to degrade petroleum products. Out of 35 isolates of yeasts tested, 77% showed assimilation of diesel, 74% kerosene and 23% crude oil. These yeast belonged to the genera Debaryomyces, Hansenula, kluyveromyces, Pichia, Saccharomyces, Candida, Geotrichum, Rhodotorula and Trichosporon. The growth rate in oil medium varied for each isolate. Among these yeasts Candida tropicalis was the most efficient in oil degradation. The potential role of marine yeasts in mediating oil degradation in marine environment is discussed.