This study used the computerised records from three general practices in Hamilton, New Zealand, to generate a comprehensive diabetes register including diagnostic codes and hypoglycaemic prescriptions. The overall prevalence of diabetes in patients aged ≥20 years was 1221/26,096 (4%). Eighty percent had attended for a ‘Get Checked’ annual review in the last 12 months. Age-adjusted analyses showed that Māori, males and those diagnosed more than 5 years ago were at increased risk of having unsatisfactory glycaemic control. Māori, Asian patients and women appeared less likely to have accessed retinal screening in the last 2 years.