Individual monitoring of glucose levels is based on repeated capillary blood glucose strip measurements. However, the reliability of this method in clinical settings is questionable. The aim of our study was to determine whether blood glucose levels measured by glucometer are acceptable in emergency departments, as is the case in some health centres. The study was conducted in a medical intensive care unit over a period of 03 months. Capillary blood glucose was measured with a glucometer in 100 patients admitted to the emergency department, compared with venous blood glucose measured in the laboratory on blood taken from the same patients. Correlation tests between the two methods were performed using Sigma Plot Statistical Analysis Software 2001. Our results showed that there was a poor relative correlation between capillary and venous blood glucose levels. In conclusion, we can say that capillary blood glucose results should be interpreted with caution in intensive care settings, as some cases of hypoglycaemia may be falsely diagnosed as normal.