Abstract: Oil saturated channel-fills which range 1-5.90 m in thickness occur in turbidite bearing Haymana formation of the Haymana region. Although most channels are single cuts, some show several related phases of cutting andfilling. The walls generally have gentle slopes, but in one channel they slope 75°. The channel-fill sediments consistof thick sandstone beds ranging from very coarse to very fine in grain size. Petrologically these sandstones are camposed mainly of lithic fragments, plagioclase and quartz and can be confidently called lithic vake ( graywacke). Onthe basis of field evidences such as interbedding of channel-fill sediments with turbiditic sandstones and being enclosed by the pelagic marls it is thought that the most likely process for the cutting and filling of the channels wasturbidity currents. Presence of sedimentary structures both on the soles and in the channel-fills which are the resultsof turbidity currents strenghten this idea. In the light of these evidences it is interpreted that this channel-fill sediments were perhaps deposited on the lower parts of the submarine fans which gradually merge in the abyssalplain. The submarine channel-fan complex is a most important type of petroleum reservoir as demonstrated by recentexploratory work in California, Carpathians, Southwestern France and other areas. Therefore the presence of oil saturated deep channels in turbidite-bearing Haymana Formation has paleogeographie significance and they will alsoattract the attention of oil companies for finding commercial oil in unexposed parts of the Haymana-Polatlı basin. Agood understanding of the evolution of the Haymana-Polatlı region and the careful sedimentological studies of theturbidite formations are essential in finding the more proximal parts of the basin where the oil is likely to be accumulated.