Hyperuricemia, commonly found in hypertensive patients, is a daily problem for the practitioner, especially those induced by diuretic therapies. The most divergent opinions are being given about the cardiovascular potential risk of hyper-uricemia. This article raises the problem of the use of those substances which change the metabolism of uric acid, whether they are hyper- or hypo-uricemic. It serves to remind that one must not prescribe hypo-uricemic diuretics to patients whose uricemia is increased, because they may involve serious risks, especially renal ones.