Objective This study aims to evaluate the suitability of the cobas b 101 instrument for the measurement of HbA1c in primary care. Methods Ten primary health care centres were involved in the evaluation of the cobas b 101 instrument. Inter-assay imprecision was assessed through quality control testing by practice nurses in the primary health care centers. Intra-assay imprecision was assessed through quality control testing by scientific staff in a laboratory setting. Accuracy was assessed through 15 patient comparison samples at each site, with samples tested on the b 101 instrument and sent to the local laboratory for analysis. Surveys were conducted assessing user satisfaction. Results All imprecision results met the minimum and desirable precision goals. Overall patient comparison results demonstrated good correlation (r ≥ 0.97). An overall instrument bias of 6.5% was seen. All laboratory-diagnosed diabetic patients were classified as diabetic on the b 101 instrument. User satisfaction results were high, recognizing confidence in the b 101 results and advantages to laboratory testing. Conclusions This study demonstrates that HbA1c testing in primary care through the cobas b 101 instrument is a suitable alternative to laboratory methods, with good precision, correlation, and user satisfaction results.