Objectives: We aimed to determine the effectiveness of glycaemic monitoring and control in the inpatient setting of a tertiary New Zealand hospital, and whether suboptimal control and monitoring may be associated with adverse outcomes in both Māori and Non-Māori diabetes patients. Methods: Clinical records including all glucose levels (n = 51,680) from inpatients ≥ 15 years old with diabetes who were admitted to Waikato Hospital for > 24 hours between 1st July 2017 to 30th June 2018 were extracted electronically from the hospital database, and the data retrospectively examined (n=3,380 patients and 4,901 admissions). Results: Overall 80.8% of diabetes inpatients had their blood glucose levels monitored. Patients experiencing ≥ 1 episode of hypoglycaemia were 1.90 times (CI: 1.37-2.64) and 1.94 times (CI: 1.51-2.49) more likely to die within 60 days and one year respectively, with an increased length of hospital stay by a mean of 3.13 weeks (CI: 2.55-3.85). Māori patients were more likely to experience ≥ 1 episode of hypoglycaemia (OR: 1.46), with a higher one-year mortality (p<0.001) as well as higher readmission rates at 30,60, 90 and 365 days than non-Māori. Blood glucose checks at least once every 24 hours were associated with shorter hospital stays (0.36 weeks) and a lower one-year mortality (Adjusted odds ratios (OR): 0.77, CI: 0.64-0.91). Conclusions: At least one episode of inpatient hypoglycaemia was associated with a statistically significant increase in 60-day and one-year mortality as well as notably longer hospital stays, with more frequent hypoglycaemia occurring in Māori patients. Significant hyperglycaemia was associated with an increased one-year mortality, higher readmission rates within one year and longer hospital stays.><0.001) as well as higher readmission rates at 30,60, 90 and 365 days than non-Māori. Blood glucose checks at least once every 24 hours were associated with shorter hospital stays (0.36 weeks) and a lower one-year mortality (Adjusted odds ratios (OR): 0.77, CI: 0.64-0.91). Conclusions: At least one episode of inpatient hypoglycaemia was associated with a statistically significant increase in 60-day and one-year mortality as well as notably longer hospital stays, with more frequent hypoglycaemia occurring in Māori patients. Significant hyperglycaemia was associated with an increased one-year mortality, higher readmission rates within one year and longer hospital stays.