INTRODUCTION Diabetes mellitus is common in primary care, yet little has been reported of its primary care prevalence or the clinical characteristics of patients with Type 2 diabetes mellitus (T2DM). AIM To determine the prevalence of diabetes mellitus and clinical characteristics of diabetes patients in primary care in the Waikato region. METHODS Primary care data were extracted from the electronic records of 15 general practices for patients aged >20 years with current diabetes mellitus at 20 June 2017. Diabetes mellitus was defined as having a glycated haemoglobin (HbA1c) of ≥50mmol/mol (6.7%) or having being dispensed two or more anti-diabetic medications in the previous 12 months. Additional data collected included patients' ethnicity, age, sex and years since diagnosis. RESULTS The overall prevalence of diabetes mellitus was 5.7% and was higher for Māori (8.6%), Asian (7.0%) and Pacific peoples (9.1%) than Europeans (5.0%; all P<0.001). For patients with T2DM for whom current diabetes annual review data were available (n=2227) the mean body mass index (BMI) was 32.8±0.2kg/m2, but BMI was higher in Māori, younger patients, females and patients diagnosed <2 years previously (all P<0.001). Similarly, HbA1c levels were highest in Māori and younger patients (both P<0.001), with 40% of patients overall having a HbA1c of ≤53mmol/mol (7.0%). Approximately 70% of all patients had at least one measure of hypertension (systolic ≥130 or diastolic ≥80mmHg), or dyslipidaemia. More than 85% of patients had completed a recent retinal screen and foot check. DISCUSSION We found that management of T2DM was suboptimal, with measures for many patients not meeting clinical targets. Support should be provided to improve weight and glycaemic management, particularly for Māori, females and younger patients.