The advancement in computer technology has encouraged the researchers to develop software for assisting doctors in making decision without consulting the specialists directly. The software development exploits the potential of human intelligence such as reasoning, making decision, learning by experiencing and many others. Knowledge based system is a computer program that uses artificial intelligence or expert system techniques to solve problems in a fashion similar to the expert. Knowledge based systems can assist physicians in diagnosing medical problems of a patient or help in the interpretation of medical test results. This book focuses on the methodological aspects of design and development of knowledge based systems that aim to support physicians in the diagnosis and treatment of tuberculosis (TB). The development of this knowledge based system involves knowledge acquisition, knowledge modeling, knowledge representation and implementation of the prototype system. Evaluation and testing of the knowledge based system was carried out and positive feedback was received from users.