The origin of the right inferior phrenic artery (RIPA) was assessed in 216 patients using arterial-phase, contrast-enhanced multidetector row helical computed tomography (CT) and that of 26 patients was confirmed by angiography. One hundred and eighty patients showed the origin of the RIPA in aorta, the celiac artery, the right renal artery or the left gastric artery on CT. The sensitivity of CT was 92%. Multidetector row helical CT provides valuable anatomical information for angiographer.