This article is a state-of-the-art review on the aerobic degradation of petroleum components that are commonly found in the environment. Numerous microorganisms have been isolated and their phylogeny and metabolic capacity to degrade a variety of aliphatic and aromatic hydrocarbons have been demonstrated. This review focuses on recent progress on how microbes degrade hydrocarbons and heteroaromatic components of petroleum contaminants directed towards better understanding of the aerobic degradation processes and their exploitation for bioremediation. The phylogenetic diversity of the oil-degrading microbes was also discussed.