The ethical calculus is described. There are four entities that have a stake in all ethical decisions. These are the individual, family, community and society at large. Values assigned to these entities can be modified by experience, cultural background, religious authority and the law. In the simple case of in vitro fertilization (IVF), there seems to be general international acceptance, except for the official position of the Roman Catholic Church, the origin of which dissent is extensively discussed. There is concern about the number of pre-zygotes/pre-embryos to be transferred, the disposition of any unfertilized egg and the reporting of results. Clear ethical considerations arise as IVF is applied in more complex situations, such as unmarried couples, the use of donor gametes and donor pre-embryos, the use of cryopreservation, intracytoplasmic sperm injection (ICSI), prenatal genetic diagnosis, surrogate gestational motherhood and research on the pre-embryo. The ethical, religious and legal acceptance of these depends on the weight given to elements of the ethical calculus as described in the chapter.