20 species of the genera Clostridium, Bacteroides, Fusobacterium and the type strains of Peptostreptococcus anaerobius, Peptococcus asaccharolyticus, Veillonella parvula and Propionibacterium acnes were examined for the production of volatile (VFA) and nonvolatile (NVFA) short-chain fatty acids using high-performance liquid chromatography (HPLC) with a column for organic acids (Aminex HPX-87H). 10 min are needed for sample preparation and the VFA and NVFA were detected simultaneously in a single chromatographic run. The total time required to run each chromatogram was approximately 60 min. With regard to the production of short-chain fatty acids in culture media it was possible to identify the species of the genera rapidly and clearly. The results illustrate the role of HPLC in determinating short-chain fatty acid products as an additional means for rapid differentiation between closely related anaerobic bacterial species. The aim of the method developed is to establish a complete automatization for the identification of anaerobic bacteria using an automatic sampling system and a microprocessor-controlled chromatography unit.