Crude oil needs to be transported from oil wells to refinery and storage facilities in one form or another to ultimately become end use products. After the successful extraction of oil from the ground it is mostly transported through pipelines where the crude oil experiences various changes in its physical and chemical properties. These rheological changes may cause numerous flow assurance problems such as wax and paraffin deposition which ultimately restricts the flow of oil. Chemical additives such as Pour Point depressants (PPDs) are used in this case for the efficient transportation of crude oil by lowering the Wax Deposition Temperature (WAT). Hence, in order to enhance the knowledge about PPDs, the mechanism of various types of Pour Point Depressant for aiding the flow of crude oil while transportation were discussed in this paper.