Like many states in the European Union, Ireland has yet to fully commit itself to genetically modified (GM) crop technology. The general position of the Irish Government is 'positive but precautionary'. However, with the European-wide de-facto moratorium on commercial production of GM crops now ended, many strategically important decisions regarding the commercial deployment of such crops and their co-existence with conventional/organic crops need to be considered. To date, little research on the environmental impact of GM crops has been carried out in Ireland, and the provision of relevant local information lags far behind that available in other countries in the European Union. In this paper, we discuss much of the new ecological and economic data that have emerged since the moratorium on GM crops was introduced in 1998, assess the likely impacts of pest-oriented GM crops should they be introduced to Ireland and examine criteria for post-release monitoring. We also describe the likely commercial demand for these crops and the consequent priorities for ecological research. We argue that the impact of GM technology needs to be assessed in relation to the environmental impact of modern agriculture as a whole. Public unease in relation to this technology may be addressed if adequate resources are made available for independent Irish research on the issue.