This paper analyses the legal and medical aspects of the work of ethics committees on abortion. According to the legislation of the Republic of Serbia, these committees are competent to determine justifiable terms for abortion after the twentieth week of the fetus. It is well known that abortion is not only a medical but a legal, ethic, social and demographic problem as well. A liberal solution in view of abortion in the first trimester has been accepted in most European countries, as by the legislature of the Republic of Serbia. Since prenatal diagnosis cannot always determine the fetus state with certainty but at times may do so at a later stage, abortion is then required when the child is already capable of extrauterine life. The necessity for performing abortion in the third trimester is thus a result of good knowledge of techno-medicine but also from the limited information it provides. In such situations, the physician needs confirmation and justification of his standpoint with respect to abortion through a legal formulation which should contain "minimum moral". Society has found a way to protect and help him through moral and ethic forms of prevention without anybody’s emotions being affected. Ethics committees should thus help the physician in view of determining the terms for performing late abortion, since the rules of doctor’s ethics are not sufficient in this case. The article especially analyses the work of the Ethics Committee of the Clinical Center in Kragujevac in the period 2000-2010. It is stated that the largest number of cases referred to determined diseases or fetus anomalies while only a negligible number (11.29%) to the illness of the mother. There were no requests for abortions due to legal reasons (pregnancies from criminal offences). A significant number (40.28%) of requests submitted to the Ethics Committee related to pregnancies under the 24th week of pregnancy. Since a pregnancy of 24 weeks represents a boundary line between a miscarriage and preterm birth, the paper proposes a shift in the boundary line of pregnancies which must be terminated according to the Ethics committee, from 20 weeks of gestation to 24 weeks of gestation. At the same time, the requirement for narrowing legal conditions for abortion in later phases of pregnancies is pointed out as well as abolition of legal indications.