Euthanasia is defined as mercy killing. It is the practice of putting death on a person who is suffering from a painful and incurable disease. Euthanasia is of two types active euthanasia and passive euthanasia. In the former type of euthanasia, a person is killed by lethal injection for example, while in the latter type a person is put to death for example by withdrawing the life-supporting system such as taking off the artificial heart-lung system. The primary aim of this research paper is to critically analyze the case of Common cause v. Union of India which is a landmark case on euthanasia in India. Along with discussing the above case other related cases also have been discussed in detail by critically analyzing them. A comprehensive discussion is made in this paper on issues related to euthanasia such as legal, moral, ethical, social and religion-based issues. Various sources have been used by the researcher in this paper such as case laws, legislations, articles, scientific journals, holy books etc for conducting effective research. In this research paper, an attempt has been made to see whether the decision given in the above-cited case laws is correct or not by comparing it with foreign nations to India. Euthanasia has a lot of issues. If it’s legalized in every part of the world it may be misused. There can be an increase in the rate of people opting for euthanasia.