Background and Objective: Diabetes mellitus is associated with an increased incidence of infections and a greater severity and frequency of related complications. In particular, the risk of hospitalization and death from infectious causes in this category of patients is double compared to euglycemic subjects. The vaccinations provided for by the National Vaccine Prevention Plan and recommended by the Italian Diabetes companies are the anti-flu, the anti-pneumococcal, the new recombinant anti-zoster, the anti -diphtheria, tetanus, and pertussis and the anti-SARS-COV2 vaccine. The goal of this work is determining the vaccination coverage for the main recommended vaccinations and for COVID-19 in the Lombard diabetic population. Methods: A chi-square test has been used to assess: whether the presence of diabetes influenced the choice to get vaccinated or not: the test was used to verify if the observed frequencies in one or more categories correspond to the expected frequencies, if the null hypothesis were true, if there are differences in terms of vaccine doses made on the basis of the type of diabetes. A statistical significance level of p-value <0.05 (5%) was used initially and, later, more conservatively p-value <0.02 (2%) due to the practical application of the correction Bonferroni hypothesis. Results: Of the total diabetic subjects, 264058 subjects (46.19%) received the influenza vaccine, 60980 (10.67%) patients received the pneumococcal vaccine, 15137 (26.25%) received the meningococcal vaccine, 4132 (0.72%) received a type of anti-Herpes Zoster vaccine. Conclusions: The vaccination coverage in diabetic population, excluding the recent anti-SARS-COV2 vaccination campaign, is currently insufficient. In general, this study has demonstrated a significant correlation between the presence of diabetes and adherence to vaccinations. Adherence is greater among patients with type 2 diabetes than in patients with type 1 diabetes: this is likely related to the presence of more comorbidities among patients with type 2 diabetes.