Hydrocarbon compounds have been noted to reside the family of neurotoxic and xenobiotic organic pollutants and nowadays petroleum hydrocarbon compounds continually being a major natural worry because of the development of petroleum oil extraction and related products which have major ecological issue. Oil seepage normally happen by mishaps pumping, transportation and refining and petroleum products consist of carcinogenic and mutagenic compounds which could have several consequences on biotic and abiotic factors of the ecosystem. Mainly two methods such as mechanical and chemical methods are normally used to remove hydrocarbons from contaminated places have effectiveness and can be expensive. Bioremediation is the best and advance technology for the treatment of these contaminated places because it is not much expensive and will lead to whole mineralization. Microbial degradation is the major and ultimate natural mechanism by which one can clean up the petroleum hydrocarbon pollutants from the environment. Many indigenous micro-organisms in water and soil are able to degrading hydrocarbon contaminants. A number of limiting factors have been recognized to affect the biodegradation of petroleum hydrocarbons. This review summarizes the microbial degradation of petroleum hydrocarbons aerobically and anaerobically and various factors that influencing the process. It may be concluded that microbial degradation can be considered as a key component in the cleanup strategy for petroleum hydrocarbon remediation.