A detailed analysis of perinatal deaths in 5 maternity hospitals in the Hunter Valley of N.S.W. was performed over a 2-year period to ascertain whether all such deaths were officially certified. There were 138 perinatal deaths identified, but of these, only 131 were registered with a medical certificate. The 7 cases not certified were all just past the borderline of the official N.S.W. definition, where a late abortion is distinguished from a stillbirth. This suggests that there is a small but significant degree of underreporting of such cases, which in turn marginally reduces the official N.S.W. perinatal mortality rate.