BACKGROUND: Hemoglobin A1c (HbA1c) levels are widely used to monitor glycemic control in diabetes mellitus patients, and various methods are used for determining HbA1c levels. The ADAMS A1c HA-8180 (Arkray, Inc., Japan) is a fully automated HbA1c analyzer based on high-performance liquid chromatography (HPLC). METHODS: The analytical performance of the ADAMS A1c HA-8180 analyzer was evaluated on the basis of its precision, linearity, correlation with the Variant II Turbo (Bio-Rad Laboratories, USA), and agreement with the National Glycohemoglobin Standardization Program (NGSP) targets. All evaluations were performed according to Clinical and Laboratory Standard Institute (CLSI) guidelines EP05, EP06, and EP09. RESULTS: Coefficients of variation (CVs) for total precision at low and high levels were 0.99% and 1.16%, respectively. The linearity was excellent with R2 = 0.99 in the range of 4.98-15.10%. Its analytical performance was well correlated with that of Variant II Turbo (r = 0.9987). The 95% confidence interval of bias between the NGSP target and the levels measured using the ADAMS A1c HA-8180 was -0.402-0.225. CONCLUSIONS: The ADAMS A1c HA-8180 showed excellent precision, linearity, correlation with Variant II Turbo, and agreement with the NGSP target. Therefore, its analytical performance is satisfactory for diagnosis and treatment monitoring of diabetes.