Objectives: To compare the linear measurements of Radiovisiography (RVG) and Digital volume tomography (DVT) to direct surgical measurements in the detection of periodontal infrabony defects. Study design: RVG and DVT images were taken prior to periodontal surgery for 28 infrabony periodontal defects. After defect debridement, direct bony defect measurements were made from the cemento enamel junction (CEJ) to the base of the defect (CEJ-BD) and to the alveolar crest (CEJ-AC) with a periodontal probe. These same measurements were made on the RVG and DVT images and then compared to the direct surgical values. Results: DVT correlated strongly with surgical measurements, whereas RVG correlated less favorably (P=0.0109, P=0.0193 respectively).No significant difference for CEJ-AC (P=0.0599) was seen between DVT and surgical measurements; however, there was a significant difference for the distance CEJ-BD (P=0.0105). Conclusion: DVT technique is significantly more accurate than RVG in the detection of infrabony periodontal defects.