Abstract Diabetes is a self-managed condition with knowledge, attitudes and practices that can influence the overall treatment and outcomes delay the complications of diabetes. However, the few reported studies published point out that: low education level, poor adherence to pharmacotherapy and diet recommendations, infrequent monitoring of blood glucose, and insulin dosage regimen are associated with higher hemoglobin levels. This study aimed to assess the knowledge, adherence medication, and complexity of pharmacotherapy in T1DM patients in Brazil. A cross-sectional study was conducted involving 156 T1DM patients who were attending in primary care. Logistic regression analyses were conducted to assess the variables associated with glycemic control. The overall assessments of T1DM patients for the glycemic control were bad (121, 77.6%). However, T1DM patients with high MedTake Test (OR=2.4, CI=1.1-5.7) and Morisky-Green Test (OR= 2.5, CI=1.1-6.1), and in the use of dosage insulin (>40 units, OR=0.3, CI=0.1-0.7) and postprandial glucose (100-125mg/dl, OR=3.8, CI=1.1-14.6) had better glycemic control compared to uncontrolled patients. Glycemic control in Brazilians adults with T1DM is low. We suggested the screening patients with low MedTake and Morisky-Green Tests, increasing patient knowledge as part of a complex intervention that may lead to substantially improved treatment outcomes in primary care