Diabetes mellitus is a condition that results in elevated blood glucose levels. Continued elevation can contribute to progressive micro- and macrovascular complications, leading to renal, nerve and ocular damage, representing a significant contributor to patient morbidity and mortality. The measurement of blood glucose provides information on the effectiveness of blood glucose metabolism and guides interventions to achieve optimal glucose control within the body. All nurses should be familiar with the importance of blood glucose monitoring and the procedure to carry out testing safely and effectively. Appropriate and timely monitoring of blood glucose will allow for the successful management of blood glucose that is out of the target range. This will ensure ongoing patient safety during episodes of acute illness or effective management of diabetes mellitus in the longer term, minimising future diabetic-related health complications.