Fenfluramine has been associated with an increased risk of pulmonary hypertension and valvular disease. Benfluorex is a fenfluramine derivative approved for the treatment of metabolic syndrome and type 2 diabetes mellitus. To date, only three isolated clinical cases of valvular disease and two recent case-control studies have been reported in patients exposed to benfluorex. Herein, the case is described of a patient with mitral and aortic valvular disease, with both echocardiographic and histopathological findings, who had been receiving benfluorex for several years, without any other etiology of valvular disease. The case is suggestive of toxic valvular lesions, similar to those observed previously during treatment with fenfluramine, pergolide, and cabergolide.