The distribution and transportation of Dissolved and Dispersed Petroleum Hydrocarbon (DDPH) were investigated in the Aegean Sea with the hydrodynamics of the water masses of the region. It is clear that distribution of this pollutant is strongly affected by physical dynamics of environment. The data were collected during cruises in November 1994, in the framework of National Marine Measurement and Monitoring Programme in the Aegean Sea. In the present study additionally the Chlorophyll-a was measured fluorometrically and there is good correlation between petroleum hydrocarbon and chlorophyll-a in the Aegean Sea. DDPH data was used to search origin of hydrocarbons: biogenic or non biogenic. © 1995, Taylor & Francis Group, LLC. All rights reserved.