BACKGROUND: The selection of identification (ID) system of enterococci depends mainly on the accuracy of ID system, cost of operation and convenience of testing. Commercial ID kits are easy to use but too expensive. The aim of the study was to develop a simple system for the identification of species of enterococci which are frequently isolated from clinical specimens. METHODS: Eight conventional biochemical tests selected for the simple ID method were hemolysis pattern, NaCl-esculin hydrolysis, tellurite tolerance, arginine dihydrolase, acid from arabinose, raffinose and methyl-alpha-D-glucopyranoside, and pigment production. Ninety one consecutive strains of enterococci from clinical specimens isolated during the period of April 1988 were tested by the simple ID method, and API rapid ID 32 STREP. RESULTS: Simple ID method with 15 ID codes was established to identify 13 species of enterococci. Among the 91 isolates tested, 88 (96.7%) were identified to the species level of enterococci by simple ID method. CONCLUSIONS: The simplified conventional ID method is simple, reliable and economical. Further modification may improve the accuracy of the enterococcal species identification system.