Abortion is one of the most controversial and contentious issues of our time. Few topics generate as much public debate or leave as little room for political compromise. This article presents a discussion of selected United States Supreme Court decisions on abortion and the legal reasoning supporting those decisions. It should be noted initially that laws regulating abortion are enacted by either state legislatures or the Congress. Disputes over abortion arise when a statute that regulates abortion in some way is challenged as being in violation of individual constitutional rights. Since 1971, there have been 28 Supreme Court decisions that have addressed various issues related to abortion. Most addressed state or federal statutes that provided specifically for abortions; a few involved statutes that addressed broader issues including abortions. Although each decision was of some importance, the major principles of law pertaining to abortion were established in three major decisions--"Roe v. Wade" (1973), "Planned Parenthood of Southeastern Pennsylvania v. Casey" (1992), and "Stenberg v. Carhart" (2000). The principles and reasoning of these three decisions are the focus of the discussion that follows.