The authors report their experiences with retrograde adrenal phlebography (RAP). Anatomy, technique, indication and diagnosis of this assay, combined with selective blood sampling from adrenal veins for determination of steroid hormones and catecholamines are discussed. These methods of investigation are believed to increase the accuracy of diagnosis and localization of adrenal gland diseases. RAP is considered the best radiological examination for the evaluation of all pathological conditions of the adrenal gland, especially in those leading to endocrine hyperfunction.