In the Tuz Gölü Basin (central Anatolia), the Karapinaryaylasi Formation (Paleocene–Eocene) is represented by shale and sandstone alternation, conglomerates and lensoid limestones. The total organic carbon (TOC) results from most outcrops and the Karapinar-2A well samples show less than 0.50 wt%, and the hydrogen index (HI) and genetic potential values are very low. In the Aktas-1A, Aksaray-1 and Sultanhani-1 wells, the TOC content is generally lower than 0.5 wt% but can reach up to 1.50 wt%. Rock-Eval pyrolysis indicates that some intervals within the Karapinaryaylasi Formation possess good gas potential, with a total yield of up to 4268 ppm. The Paleocene–Eocene rocks are thermally immature to marginally mature with respect to Tmax, ranging from 420°C to 458°C, while vitrinite reflectance and spore colour index values range from 0.50% Ro to 0.88% Ro and 4 to 8(?), respectively. Microscopic investigations and the HI vs. oxygen index (OI) and HI vs. Tmax diagrams show that the samples contain Type III and Type II kerogen, which is often oxidized, together with reworked material. Gas chromatography and gas chromatography–mass spectrometry analysis results support these conclusions. Consideration of all the data indicates that the Karapinaryaylasi Formation (Paleocene–Eocene) could be the source rock for gas production in the Tuz Gölü Basin.