OBJECTIVES: HbA1c concentrations predict the risk of complications in patients with type 2 diabetes mellitus (T2DM). This study assessed temporal trends in elevated HbA1c levels in the UK primary care setting.  METHODS: T2DM was identified by medical diagnosis, prescribing, elevated blood glucose and/or prescribing of monitoring devices. Patients had ≥12 months of CPRD history, with data available for the entire year of observation. T2DM patients prescribed insulin were excluded. Mean HbA1c levels and proportion of patients with elevated HbA1c were assessed across six years (01/04/2006–31/03/2012). Elevated HbA1c was defined according to the UK Quality and Outcomes Framework (QOF) threshold: >7.5% for all years except 2009/2010 (>7.0%). Estimates were stratified by age-band, gender, T2DM-status and treatment categories. RESULTS: Mean HbA1c levels among 176,428 patients were relatively stable and below threshold across the study period (2006/2007: 7.05%; 2011/2012: 7.16%), with the exception of 2009/2010 (7.09%). Nonetheless, >20% of patients had a record of elevated HbA1c in each year (36.7% in 2009/2010). Elevations were more common among males than females (20%-25.0% versus 18%-20%) and among patients 40-59 years (27.2%-33.7 %) versus those ≥60 years (15.9%-23.3%). Although elevations were similar among prevalent (20%-23%) and incident-T2DM (22%-23%), prevalent-T2DM showed an increasing trend in the proportions with an elevation over time, whilst incident-T2DM showed a decreasing trend. The proportion with elevated HbA1c varied by treatment: diet and exercise 4.8%-6.1%; monotherapy 24%; dual therapy 32.7%-38.0%, and; triple therapy 42%-50%. Over 80% of patients with elevated HbA1c were overweight or obese, >20% had a 10-year Framingham Risk score >20% (patients without existing CVD) and 17%-21% of patients had history of chronic renal failure. CONCLUSIONS: Although mean HbA1c concentrations were below target (apart from 2009/2010), elevated HbA1c was present in >20% patients across all years. Further efforts are needed to help patients to achieve adequate glycaemic control.