This paper examines some epidemiological factors associated with SIDS to give a general profile of SIDS cases occurring in Ireland between the years 1993 to 1997. There has been a dramatic decrease in the incidence of the Sudden Infant Death Syndrome (SIDS) in the Republic of Ireland in the last decade from an average rate of 2.2/1000 live-births in the 1980s to 0.8/1000 live-births in the years 1993-1997, a decrease of 100 deaths a year. The fall in the SIDS rate has been seen in many countries and is felt to be associated with Reduce The Risks (RTR) of SIDS campaigns and the avoidance of the prone sleeping position. The use of the prone sleep position averaged at 6% of children being put prone in the years 1993-1997 but the prone position has progressively decreased from 13% of children being put prone in 1994 to only 2% in 1997. The profile of the Irish SIDS cases is similar to that of SIDS cases in other countries following similar RTR campaigns with a male predominance, the characteristic clustering of deaths in the first six months of life and the majority of cases (75%) occuring in the night sleep period. The loss of the seasonal variation of the time of death is also shown and factors such as lower socio-economic status, unemployment and medical card eligibility were seen in higher proportions in SIDS families than in the general population. A high percentage of SIDS mothers smoked (73%). Higher smoking rates were seen among younger and single mothers and smoking rates were inversely related to educational level and socioeconomic grouping. An urgent question that needs to be addressed is how socioeconomic disadvantage increases the SIDS risk and what factors influence socioeconomically disadvantaged families to adopt life style and parenting practices such as smoking that influence their children's health.