Aim of the research: The main goal of the research is the interpretation and evaluation of the results obtained through questionnaires administered to patients of the diabetes clinic at the General Hospital Šibenik. Statistical data processing methods were applied to analyse the results. The questionnaire was designed to address the suitable variables selected to verify the hypothesis (collecting anamnestic data on diabetes patients, compliance with the prescribed treatment and assessing the quality of life and patient working capability). It is hypothesized that better education of patients and adherence to prescribed diabetes treatment leads to more successful management of disease signs and increases the quality of patients’ lives. Examinees and methods: The study was conducted at the General Hospital Šibenik, and included subjects enrolled in the diabetes day clinic. The questionnaire was conducted on 72 respondents in the period from July 1, 2021 to September 30, 2021. The questionnaire consists of collecting anamnestic data of diabetes patients, compliance with the prescribed treatment and assessment of the quality of life and patient work capability. Results: In the conducted research, the largest percentage of respondents, as many as 93,1%, followed the recommended treatment. Although the percentage of patients adhering to treatment is high it cannot be considered as sufficient, especially in relation to the numerous complications arising from noncompliance with treatment or control of disease signs. 86,1% of respondents have at least one health complication related to diabetes. According to 48,6% of respondents, the most common complications are fatigue and inability to perform physical activity. Complying with the prescribed treatment and following the guidelines on lifestyle to manage diabetes should reduce the occurrence of these complications. In the groups of respondents who received education about management of disease signs and improvement of the quality of life from doctors or nurses, a smaller number of complications was found compared to the group of patients using other educational resources. Respondents in the survey themselves assessed the quality of life with diabetes on a scale of 1-10, with 10 indicating a high quality of life. The mean value of the quality of life assessment is 7, whereas the majority of respondents report fear of disease worsening (43,1%). 93,1% of the respondents state that the advice received from the medical staff helped to maintain and improve the quality of life, 5,6% state that the advice were partly helpful, and 1,4% of the respondents state that the advice did not help them at all. Conclusions: Complications of diabetes are the leading cause of death in patients. According to the obtained results, the vast majority of patients with type 1 and type 2 diabetes adhere to the recommended treatment and thus reduce the possible complications of the disease. The importance of good education and informing patients with diabetes is equally important from the point of view of doctors and nurses, as shown by the results confirming that the advice received from medical staff has helped to improve the quality of patients’ lives.