The objective of this study is to summarize studies and investigations and show a brief details of different technologies used for the treatment of petroleum wastewater. The wastewater from Petroleum industries and refineries mainly contains oil, organic matter and other compounds. The treatment of this wastewater can be carried out by physical, chemical and biological treatment processes. Treatment of petroleum wastewater has two stages, firstly, pre-treatment stage to reduce grease, oil and suspended materials. Secondly, an advanced treatment stage to degrade and decrease the pollutants to acceptable discharge values. Most studies are focused on degradation of some pollutants found in the petroleum wastewater such as organic materials, phenols, sulphides and ammonia.