PIP: This study examines the propostion that infanticide is a terminal abortion procedure, practiced when abortion attemps fail, or when the decision to kill an infant is based on characteristics that can be observed only after birth. Infanticide is defined as the deliberate killing of a child by any realistic means including exposure, but excluding accidental or magical means of death. Data on infanticide in 57 societies was collected to determine 1) when infanticide was performed (most often at birth), 2) who performed it (most often the mother), and 3) what kinds of infants were the victims (most often the illegitimate, twins or triplets, and the weak and deformed). There is also data on the time of the birth ceremony, who performed the ceremony, and who received it. It is found that infanticide takes place before the infant's birth ceremony and that the reasons for abortion and infanticide are similar. The victims of infanticide are viewed as fetuses and not newborns. The authors conclude that the majority of societies practicing infanticide do so for reasons that probably benefit women and apparently do not harm them. Appended to the article is a table of categories for coding data on infanticide by each society studied.