BACKGROUND: Measurement of hemoglobin A(1C) is used as an objective measure of long-term blood glucose control in diabetic patients. We evaluated recently improved hemoglobin A1C autoanalyzer (VARIANT(TM) II Hb A(1C) analyzer, Bio-Rad, CA, USA) using ion-exchange high performance liquid chromatography (HPLC) method. METHODS: Linearity, precision, comparison with IMx glycated hemoglobin assay (Abott Laboratories, IL, USA) and throughput were evaluated. The reference range was determined from 144 healthy subjects. RESULTS: The VARIANT(TM) II was founded to be linear in a range of 5.6% to 14.0% (r2=0.997). The within-run and between-day precision were 1.09% and 3.72% for low level (7.9%), 0.39% and 2.5% for middle level (9.2%), 0.7% and 1.86% for high level (14.1%), respectively. Comparison study between VARIANT(TM) II and IMx showed good correlation with a slope of 1.164, an intercept at -0.41415, and coefficient of correlation was 0.9574. The throughput of VARIANT(TM) II was 15.9 samples per hour and the reference range was 5.1-6.5%. CONCLUSIONS: The VARIANT(TM) II Hb A(1C) analyzer provides improved precision, accuracy and adequate throughput, and the instrument is suitable for use of clinical laboratory.