The objective of this study was to analyze the possible relationship between the glycemic control and the prevalence of apical periodontitis in type 2 diabetic patients. The null hypothesis was that apical periodontitis is not associated with glycemic control. In a cross-sectional design, the radiographic records of 216 type 2 diabetic patients (65.0 ± 10.7 years), 117 men (54.2%) and women (45.8%), were examined. Glycated hemoglobin (HbA1c) was used to assess glycemic control, considering an HbA1c level < 6.5% as well-controlled diabetes. Apical periodontitis was diagnosed as radiolucent periapical lesions using the periapical index score. The Student t test, chi-square test, and logistic regression analysis were used in the statistical analysis. The average HbA1c value was 7.0 ± 2.2%. Forty seven (21.8%) had HbA1c levels under 6.5% (mean ± SD = 6.0 ± 2.2%), being considered well-controlled patients, and 169 (78.2%) had an HbA1c level ? 6.5% (mean ± SD = 7.8 ± 2.24%), being considered poor controlled patients. Forty four per cent of diabetics had apical periodontitis, 12.5% had root-filled teeth, and 52.3% had root filled teeth with radiolucent periapical lesions. No significant differences were observed in any of these three variables between patients with good or poor glycemic control. In the multivariate logistic regression analysis the presence of radiolucent periapical lesions in at least one tooth did not correlate significantly with HbA1c levels (OR = 1.4; 95% C.I. = 0.70 ? 3.09; p = 0.31). The results reveal no association of glycemic control with the prevalence of apical periodontitis or root canal treatment in diabetic patients.