Objectives: The general objectives of this research are tofurther our understanding of the distribution and incidence of heavy weight births and to examine differentials in the use of cesarean section as a response to macrosomia in models that are more broadly comparative by race/ethnicity than any that have heretofore been estimated. Methods: The data are drawn from the combined 1989–1991 NCHS Linked Birth/Infant Death Cohort Files,a data set of over 12 million live births and over 100,000 infant deaths that allows for highly reliable estimations for relatively small race/ethnic sub populations. Results: The results confirm that previously identified determinants of macrosomia such as maternal diabetes,maternal weight gain, parity and a previous heavy weight infant are highly predictive of a macrosomic birth, independent of race/ethnic effects. With respect to the management of heavy weight births, race/ethnic differentials exist in the odds of a cesarean delivery, theprocedure most often used to limit the risks of a macrosomic delivery.