Paleozoic and Mesozoic outcrop and core samples (REMINA-Dekese and REMINA-Samba wells) covering various stratigraphic intervals from the central Congo Basin were analyzed for total organic carbon (Corg), total inorganic carbon (Cinorg), and total sulfur content. Rock-Eval analysis and vitrinite reflectance (Ro) measurements were performed on the basis of the Corg content. Fifteen samples were chosen for molecular organic geochemistry. Nonaromatic hydrocarbons (HCs) were analyzed by gas chromatography (GC) flame ionization detection and GC mass spectrometry. Samples of the Alolo shales from the Aruwimi Group (Lindi Supergroup, late Neoproterozoic to early Paleozoic) are in general very poor inCorg (most samples <0.5%) and contain a high amount of degraded organic matter (OM). All samples of this group revealed a type III to IV kerogen and cannot be considered as a potential source rock. Permian Carboniferous sediments from the Lukuga Group (REMINA-Dekese well and outcrop samples) contain moderate contents of organic carbon (<2%). The Tmax values (heating temperature at which top peak of S2 occurs) indicate early mature OM, partly also a higher level of maturity because of Ro (0.6 0.7%) and production index values (S1/S1 + S2 < 0.2). All samples contain hydrogen-poor type III to IV kerogen with low HC generation potential, only having a very minor gas generation potential. The kinds of OM, as well as the biological markers, indicate a terrestrial-dominated depositional environment.