Expert System for diagnosis of Selected Cardiac Diseases will be a knowledge-based system capable of making multiple diagnoses for Selected Cardiac Diseases. Expert System for diagnosis of Selected Cardiac Diseases will be designed as an information system as an decision support system application, which will provide assistance in the diagnosis of Cardiac disease and will demonstrate the assistance of a microcomputer-based expert system for medical diagnosis related to Selected Cardiac Diseases. We have thought of implementing Expert System for diagnosis of some Selected Cardiac Diseases because Heart diseases are the leading cause of death today, and causing about million deaths per year in the Society. The Cardiology has estimates that there is shortage of specialists, and the worrying fact is that the majority of electrocardiograms are analyzed by general practitioners in out-of-hospital environments. By effectively and efficiently decentralizing decision-making by means of a Expert System for diagnosis of Selected Cardiac Diseases will be a solution for effective interaction between patients, general practitioners and cardiologists even will be useful to train junior doctors and will aim to achieve a satisfactory solution to Physicians and General Practitioner‘s needs.