Science is such a subject; needs to be devoid of any biasness and prejudice. Among the different branches of science, the most practical branch is ?Health science?, which deals with the life directly by the means of health education, health care delivery and prevention of the pathological conditions. There are several different systems of medicine exist in the world, named Allopathy, Homoeopathy, Ayurveda, Siddha, Unani etc. based on different principles. Among these systems, Homoeopathy is considered as the most controversial system for the so-called scientific community, as it is little difficult to understand materialistically. As it is little bit of different from usual path, they generally consider it as ?pseudoscience? and ?placebo effect.? We are instituting this study from a neutral point of view, not tilted towards any medicinal system for explaining the most debatable question of the century ?what is the mechanism of action of Homoeopathic medicines?. Many people said, ?I do not have faith on Homoeopathy/ Allopathy/ Ayurveda etc.?, but to say very clearly that, ?any of the scientific phenomena does not require any faith on it, they work in their own way spontaneously without bothering anyone?s belief or disbelief?. In this study, we are taking some medicines and some diseases, because it is nearly impossible to describe all medicines and all diseases in a particular research work. Every system of medicine has its own scopes and limitations; so it is useless and immaterial to declare any of the systems as unscientific without any clearly defined reason just based on their self-preference or any particular business purpose. It is not only the fault of few scientists or people, rather it is a fault of homoeopathic researchers and doctors also, because they do not feel any need to prove the ?Modus operandi? of Homoeopathic remedies, as in an aphorism of ?Organon of Medicine? Dr. C.F.S.Hahnemann had written, knowledge about the modus operandi of Homoeopathic medicines is not much important than giving aid to the suffering society. We have taken several patients with different diseases as the control, then we have applied the needed homoeopathic remedies accordingly and have done several pathological examinations and clinical examinations not considering the feeling of the particular patient, as for few people, feeling may be subjected under the ?placebo effect?. Finally, we have tried to figure out the mechanism of action of Homoeopathic remedies in a simple and clearly defined manner.