PURPOSE To validate ANCOR, a new system in quantitative coronary arteriography (QCA). MATERIAL AND METHODS The validation procedure was performed by comparing the calibration factors of catheters filled with saline solution or contrast medium, and by measuring precision-drilled lumens in a test phantom filled with contrast medium. The results were compared with a well established and validated system, CMS. RESULTS The calibration test showed that the calibration factors in the saline and contrast-medium catheters differed only a few percent when catheters with diameters of 2.0-2.67 mm were used. The phantom test showed that both systems overestimated smaller and larger diameters than these. The best results for both systems were achieved in the middle-diameter range. CONCLUSION The ANCOR and CMS systems gave comparable results in catheter calibrations and phantom tests.