Two trials of external quality assessment for clinical microbiology laboratories were performed in 2008. A total of 16 specimens were distributed. Eight specimens were distributed to 330 laboratories with 319 (96.7%) returns in Trial I, and 8 specimens to 335 laboratories with 319 returns (95.2%) in Trial II. Two slide specimens for mycobacterium stain (AFB) were distributed in Trial I and II. The acceptable percentages of Gram stain were relatively good for both stainability and morphology except for Acinetobacter baumannii. The acceptable percentages of bacterial identification (correct answers to species level) on Klebsiella pneumoniae, Staphylococcus aureus, Neisseria meningitidis, Serratia marcescens, Erysipelothrix rhusiopathiae and Candida albicans (Trial I) were 97.4%, 99.2%, 55.6%, 97.0%, 79.2%, and 92.0%, respectively. The acceptable percentages of bacterial identification on A. baumannii, Enterococcus faecalis, Streptococcus pyogenes, Haemophilus parainfluenzae, Elizabethkingia meningoseptica, and Yersinia pseudotuberculosis (Trial II) were 92.0%, 90.8%, 4.5%, 53.1%, 74.8% and 94.3%, respectively. The acceptable percentages for antimicrobial susceptibility tests on K. pneumoniae and S. aureus (Trial I), and A. baumannii and E. faecalis, (Trial II) were relatively good compared to data of the last year. The acceptable percentages for AFB stain in Trial I and II were relatively high. In summary, the acceptable percentages of bacterial stain and identification were relatively good except some cases with poor specimen quality. However, it is still necessary that the quality assurance of the individual laboratories should be improved for antimicrobial susceptibility tests, and the selection of the most appropriate antimicrobial agents to test should be also considered.