This review paper showcases the various kinds of practical muffler designs available and attempted by several researchers and pioneers in muffler designing. The various design methodologies, design principles and lead factors that they have considered while designing is explained in this paper. The objective behind this study is to have a satisfactory knowledge about the various elements that comes into being when muffler designing is put forth to practice. The transmission loss and backpressure of the exhaust muffler, has been the key factor of consideration in most of the works done by the researchers as these have a direct impact on the engine performance, exhaust noise attenuation and finally fuel efficiency of the engine.