Abstract: To provide highly safe therapeutic or preventive agents for hyperuricemia, more specifically uricosuric agents, which have potent uricosuric effect and do not cause grave hepatic disorder. Medicinal compositions for the treatment or prevention of hyperuricemia or diseases caused by hyperuricemia, which contain 6-hydroxybenzbromarone or salts thereof, and pharmaceutically acceptable carriers; uricosuric agents, xanthine oxidase inhibitors, and inhibitors against the uptake of uric acid in kidney, which contain 6-hydroxybenzbromarone or salts thereof; and a process for the production of 6-hydroxybenzbromarone.