The heart is the most important of the vital organs and heart diseases may cause fatal consequences. Abnormal heart sounds called murmur may be a precursor of many serious heart diseases. Cardiac auscultation is a basic technique to easily diagnose murmur disease. Auscultation can be supported by using computer aided automatic diagnosis systems to fast and accurate diagnosis. These systems are useful to remote diagnosis systems in place that have the lack of physicians and modern techniques. In this study, heart sound data taken from different patients and recorded with the help of an electronic stethoscope are classified by using Hidden Markov Model. At the end of this study, healthy heart and five different murmur diseases; can be detected with full success just listening heart sound by an automatic system.