It is extremely helpful for the examiner to separate murmurs of nonorganic origin into one of two categories. The innocent heart murmur group defines five specific entities: the pulmonary systolic murmur, the vibratory systolic murmur, the supraclavicular systolic murmur, the mammary souffle, and the venous hum. All other nonorganic murmurs are classified as functional, and are produced by clinically recognizable alteration in anatomy and/or physiology affecting the circulatory system. This paper discusses each category and provides information regarding bedside diagnosis of selected murmurs.