Abstract: Homeopathy treats patient on the basis of totality of symptoms and is based on the standard of 'like cures like'. It uses ultra-low doses of exceptionally weakened characteristic substances as remedies that start from plants, minerals or animals. The main purpose of this survey is to discuss concepts, controversies and research identified with understanding homeopathy in the light of modern science. Attempts have been made to focus on current views of homeopathy and to outline its most plausible mechanism(s) of activity. Although some areas of concern remain, research did so far both in vitro and in vivo validates the effects of much weakened homeopathic medicines in a wide assortment of organisms. The precise mechanism(s) and pathway(s) of activity of profoundly weakened homeopathic drugs are still obscure.