The study evaluated the effects of a standardized nursing care program on diabetic patient outcomes and nursing competence in a primary care hospital. The control group consisted of 56 nurses and 80 patients with routine care (May 2021 - May 2022), the observed group consisted of the same number of nurses and 80 new patients after the intervention (June 2022 - June 2023). The intervention included systematic training of nurses on diabetes and implementation of a standardized model of care. After training, nurses in the observed group had significantly higher operational and theoretical scores (p < 0.001). Patients in the observation group had higher diabetes knowledge scores (p < 0.001), lower fasting glucose (6.25 ± 0.45 mmol/l vs. 6.5 ± 1 mmol/l) and HbA1c (6.50 ± 0.25% vs. 0.20%; p < 0.001), lower incidence of adverse reactions (p = 0.034) and higher satisfaction. (p = 0.003). Data were analyzed by t-test, ANOVA and chi-square test.