The Reverend George Crabbe, a Church of England clergyman, published his poem The Parish Register in 1807. For him, his registers were ‘The simple annals of my Parish poor’, and he reflected on the human stories behind his entries within them, concluding rather gloomily that for his parishioners ‘Their joys come seldom and their pains pass slow’. The destruction of so many of Ireland’s historical records in the Public Records Office in 1922 and on other occasions makes the surviving parish registers, however ‘simple’ (and partial) the information they contain, a hugely informative source for the study of communities in the past. However, there seems to be limited appreciation of their treasures. Though the National Library’s Catholic Parish Registers online has rightly been hailed as an important resource for those interested in genealogy and family history, little mention has been made of the huge potential of these records as sources for demographic, social and cultural history - along with the earlier Catholic registers and the surviving registers of the Church of Ireland and other Protestant denominations that have not yet been digitised in any coherent manner. This is despite the insights provided by the Cambridge Group for the History of Population and Social Structure’s work on English parish registers, and the fact that several historians and geographers have already used Irish registers as sources for the study of communities in, for example, Wicklow, Dublin, Wexford and Derry. This paper therefore is a plea for greater use of the parish registers, using case studies to highlight some of the ways in which they can cast light on the joys and pains of Catholic and Protestant parishioners from the seventeenth to the nineteenth centuries. Among other things, the registers reveal valuable information on topics like illegitimate birth and parenthood; the role of networks of friendship and association within communities; courtship, marriage, family formation, birth spacing and child rearing; and details of causes of death, especially in infancy and as a result of epidemic disease