ObjectiveDiabetes mellitus (DM) is a chronic disease considered an important public health problem. In recent years, its prevalence has been exponentially rising in many developing countries. Chronic complications of DM are important causes of morbidity and mortality among patients, which impair their health and quality of life. Knowledge on disease prevention, etiology, and management is essential to deal with parents, patients, and caregivers. The aim of this study was to evaluate the knowledge regarding DM in an adult population from a Middle-western Brazilian city.MethodsThis was a cross-sectional study covering 178 adults, aged 18–64 years, who answered a diabetes knowledge questionnaire. In order to identify the difference between groups, analysis of variance was used.ResultsHigher knowledge scores were found regarding the role of sugars on DM causality, diabetic foot care, and the effects of DM on patients (blindness, impaired wound healing, and male sexual dysfunction). However, lower scores were found amongst types of DM, hyperglycemic symptoms, and normal blood glucose levels. Females tended to achieve better knowledge scores than males.ConclusionWomen had better knowledge regarding types of DM, normal blood glucose values, and consequences of hyperglycemia revealed that diabetes education should be improved.