The Haymana Basin, one of the central Anatolian Basins of Turkey, developed from Late Cretaceous to Middle Eocene during closure of the northern branch of the Neo-Tethys Ocean. The basin is located to the south of Ankara and has been explored for oil and natural gas since the 1950s. To date, there is no commercial production of oil and natural gas in the basin, however, there was one wildcat well drilled in 1976. The well targeted the Haymana Formation but it did not produce any hydrocarbon. The most important sedimentary rock units with hydrocarbon potential in the basin are the Maastrichtian Haymana and the Paleocene Kırkkavak formations. For many years, the Haymana Formation was considered the main potential source rock even though it has low total organic carbon (TOC) values; in general less than 0.5%. Hydrocarbon potential of the Kırkkavak Formation has remained poorly understand because of lack of research focused on the formation. During this study, a complete section of the Kırkkavak Formation, exposed in the northern part of the basin, is studied in order to determine sedimentary environments and hydrocarbon potential of the unit. The section, containing oil seeps in many locations, was measured in detail and samples were collected systematically for petrographic and geochemical analyses. The geochemical analyses were conducted on the samples to determine total organic carbon (TOC in wt %), oxygen (OI) and hydrogen indexes (HI), Tmax, production index (PI), and generating source potential (S2). Several samples exhibit good TOC, Tmax, and HI values. The results suggest that the middle part of the Paleocene Kırkkavak Formation (~60 m) contains very good source rock with Type II kerogen, which produces mostly oil and little gas. However, the geochemical analysis suggests that the lower (~70 m) and upper (~200 m) parts of the formation should be considered immature zones based on the Tmax and PI values.