RESUMEN
OBJECTIVE: Evaluate laboratory performance on blood smear examination among public and private health laboratories. MATERIAL AND METHOD: External Quality Assessment Scheme (EQAS) for blood smear examination was organized by the Department of Medical Sciences. The scheme was run in 2005 by sending out six blood smears with normal and various abnormal types of blood cells. Participants were from 731 public and 181 private hospitals with hematology laboratories throughout Thailand RESULTS: Analysis showed good performance on identification and differentiation of leukemic blast cells and atypical lymphocytes. In addition, good performance was found in platelets reports. However, unsatisfactory performance was found on identification of red blood cells morphology. CONCLUSION: The present study suggested that the error reported of red blood cell morphology should be further investigated and the problems for improving laboratories performance solved.