Two cases of PA-VSD were examined by computed tomography angiography (CTA) using dual-source 128-MDCT to reveal the anatomy and morphology of the pulmonary circulation. The first case was diagnosed as PA-VSD type B, while the second case was diagnosed as PA-VSD type A. These cases show that dual-source 128-MDCT can be used to provide clinical information for PA-VSD with the appropriate examination protocols and post-processing techniques.