Bacteria and yeasts from different niches of the tropical Indian waters were screened for their hydrocarbon degrading potential using 1% w/v in artificial seawater over a period of 6 days. About 20% of the 75 bacterial and 24% of the 27 yeast strains were found to degrade crude oil. Some of the bacterial strains could degrade more than 90% of the aliphatic fractions and more than 50% of the aromatic component. These could also oxidize pure aromatics like naphthalene (80%) and anthracene (55%). Among the yeasts one strain could degrade 90% of the aliphatics and 22% of the aromatics and another 45%of the aliphatics and 41% of the aromatics. While both bacteria and yeast were able to degrade aliphatic fractions up to C sub(20), the yeast strain MY11 could degrade fractions from C sub(20)-C sub(30) almost completely. One of the bacterial strain was a phosphate solubilizer and another a nitrogen fixer. Screening of the hydrocarbon degrading bacteria showed that most of them harboured extra chromosomal elements (2-25Kb).One of them showed multiple plasmids. Fatty acid profile showed the bacteria to be mainly Pseudomonas sp. and the yeast to be Candida sp.