Abstract At least twelve organic-rich layers, so-called sapropels (S 1–S 12), occur in Late Quaternary sediments from the eastern Mediterranean. Organic matter in sapropel S 7 (organic carbon up to 11%) is characterized in detail by gas chromatography (GC) and gas chromatography-mass spectrometry (GCMS). Lipids were thus separated to obtain information about their mode of occurrence. This procedure separates the lipids into three classes: (1) free lipids extracted by Soxhlet extraction; (2) residual bound lipids extracted after saponification of the Soxhlet-extracted residue; and (3) residual bound lipids extracted after acid treatment of the saponified residue. In addition, an extract was obtained after saponification of the free lipids. The organic matter investigated is of a mixed marine (e.g. dinoflagellates, coccolithophorids), terrigenous (e.g. cuticles) and bacterial origin with the former predominating. The formation of sapropel S 7 is probably caused by a combination of stagnation and high productivity, both induced by a large input of fresh riverine water, carrying nutrients and terrigenous organic material.