The aim of this study was to explore the perceived knowledge of diabetes among personnel practising in municipal care. The study was conducted using a qualitative approach through focus group interviews. The study included focus group interviews on three occasions, with a total of 22 enrolled nurses (ENs). The results showed that the ENs' perceived knowledge of diabetes was not optimal. However, the study findings demonstrated that the ENs felt they had sufficient knowledge of nursing interventions, especially in the prevention of foot complications. Nevertheless, they expressed feelings of insecurity about assessing symptoms, treatment, and interventions to be taken with high or low blood glucose levels. When providing opportunities for educating ENs prior to delegating to them the task of insulin administration, the training sessions should be structured and led by a diabetes nurse with pedagogical skills. It is important that the registered nurses who teach have up‐to‐date knowledge concerning developments and research in diabetes care. The results of the study show that ENs employed within municipal health care lack knowledge regarding the care of older people with type 2 diabetes. Therefore, it is essential that ENs receive structured education and training in diabetes in order to ensure good and safe diabetes care. Copyright © 2012 FEND. Published by John Wiley & Sons, Ltd.