Several dynamic tests with vasoactive drugs are available for evaluating penile vascular inflows and outflows, ranging from simple pharmacologic test to more invasive radiologic sets. However, there is still no perfect single test to reflect the penile vascular flow. All possible efforts should be exerted to get the greatest erectile effect to avoid an underestimation of blood flow to the corpora due to incomplete relaxation of the trabecular smooth muscle. Appreciation of the type and frequency of anatomical variations and potential collateral routes is important in interpreting penile arterograms and in evaluating the hemodynamic significance of suspected arterial disease. Choice of the vascular tests should always depend on the purpose of testing.