(1) The concept of perinatal mortality has been introduced and discussed. (2) The recent studies and researches embodied in the Reports of the three Lying-in Hospitals in Dublin have been discussed in this respect. (3) The matter of stillbirths in the practice of the Dublin Lying-in Hospitals has been considered and an estimate made of the national stillbirth numbers. (4) The neo-natal deaths occurring in the three Dublin Lying-in Hospitals have been reviewed and related, as regards causes and rates, to the national figures for neo-natal deaths. (5) The national figures for neo-natal deaths are analysed briefly as regards sex, areas, etc. (6) Perinatal mortality in Ireland is considered as regards causes of death under the headings of ante-natal, natal and post-natal causes. (7) The findings are discussed briefly with special reference to the reduction in perinatal mortality.