Objective. To identify the proportion of poor of glycemic control and associated factors among people with type 2 diabetes attending a regional reference outpatient clinic in Mato Grosso (Brazil). Methods. This is a cross-sectional quantitative study based on data from medical records of 338 people with type 2 diabetes who attend a state reference outpatient clinic in Mato Grosso (Brazil). Information on glycemic control, sociodemographic factors, lifestyle and clinical conditions was collected. Results. The prevalence of elevated glycated hemoglobin was 47.34%. In the Poisson multiple regression model analysis with robust variance, poor glycemic control was significantly associated (p<0.05) with the following factors: insulin use (Prevalence Ratio -PR = 2.03), fasting glucose ≤70 and ≥100 mg/dL (PR = 2.0), postprandial glucose ≥180 mg/dL (PR = 1.76), no physical activity (PR = 1.62), the interaction between age group ≤59 years and the time of disease diagnosis >10 years (PR = 1.58), and presence of arterial hypertension (PR = 0.79). Conclusion. Most users of the reference outpatient clinic with type 2 diabetes had poor glycemic control associated with risk factors that alter glycated hemoglobin and negatively affect the achievement of established glycemic levels.