The right renal artery passing anterior to the inferior vena cava is a rare variant of the normal renal arterial anatomy, and identifying this anomaly is important for the planning of minimally invasive renal surgery. The presence of this precaval right renal artery was detected on the contrast-enhanced CT scan by identifying the right renal artery passing anterior to the inferior vena cava. We report here on a case of a precaval right renal artery as a main supplying artery, and this was incidentally found on CT.