An apparatus which couples a laser microprobe with a GC-MS has recently been constructed in our laboratories to facilitate analytical micropyrolysis studies. The utility and versatility of the technique is demonstrated through the analysis of micro-sized quantities of various organic fossils. Results are reported from a torbanite coal, Green River oil shale, Tasmanite oil shale, an isolated Tasmanites microfossil and oil-bearing fluid inclusions. A diverse range of aliphatic products including distributions of n-alkene/n-alkane pairs, isoprenoids, polycyclic biomarkers and various alkylaromatics have been detected from these materials. The analytical credibility of the laser micropyrolysis GC-MS technique is confirmed by the favourable comparison of the laser derived molecular data to corresponding data obtained from more traditional methods. (C) 1998 Elsevier Science Ltd. All rights reserved.