In this article, we present the case of a patient with classic signs of Barlow’s disease and discrete mass on the posterior myxomatously altered cusp that were observed on echocardiographic examination. Barlow’s disease is a degenerative disease of the mitral valve in which leaf prolapse and mitral regurgitation occur, which is a significant cause of cardiovascular mortality and morbidity. Papillary fibroelastoma of the heart is a rare benign tumor of the heart, mostly located on the valves, it is detected incidentally, but it can be the cause of transient neurological defects and ischemia of the heart due to embolization or prolapse in the coronary ostia. Differentiating degenerative mitral valve disease is important, because choice of surgical correction techniques depend on this distinction, and pathohistological analysis (classical, histochemical and immunohistochemical staining) contributes to the confirmation of the diagnosis, which is important for future outcome research.