Purpose: To compare diagnostic value of multi-detector CT and echocardiography in the diagnosis of TAPVC Material and Method: Total 20 patients with surgically proven TAPVC were enrolled. Echocardiography and MDCT were independently interpretated by pediatric cardiologist and cardiac radiologist, respectively. Type of TAPVC, stenosis of vertical vein or not, drain site of vertical vein, course of collateral pathway in case of vertical vein stenosis were recorded. Results: In all patients, MDCT correctly depicted type of TAPVC, stenosis of vertical vein, drain site of vertical vein, developed collateral pathway in case of vertical vein stenosis. Echocardiography also correctly diagnosed in the type of TAPVC in all patients, however, detection rates of stenosis of vertical vein, drain site of vertical vein, developed collateral pathway in case of vertical vein stenosis were 57% (4/7), 85% (17/20), 0% (0/2), respectively. Conclusion: Although echocardiography was first line modality in the diagnosis of TAPVC, MDCT was needed for evaluation of stenosis of vertical vein or not, drain site of vertical vein, course of collateral pathway in case of vertical vein stenosis