Care planning for children who enter care can be influenced by a range of factors. In Northern Ireland, there are differences in the proportions of children in different types of placements across the five Health and Social Care Trusts (equivalent to local authorities in England and Wales). The aim of the study was to identify the reasons for these differences. In order to do that, focus groups in each of the Trusts were conducted with social work professionals involved in care planning. Based on the study findings, an ecological model of decision-making in care planning is postulated. Differences among all of the Trusts were found within the model’s three levels, despite all of the Trusts operating under the same broad policy framework for care planning. For instance, different mindsets were evident, as participants in some of the Trusts clearly equated the notion that children should be provided with a permanent home with adoption, while in focus groups in other Trusts, this mindset did not prevail. In addition, the Trust structures and initiatives differed slightly and there were differences in the global context factors influencing decision-making. Based on these findings, we believe regional practical guidance and policies should be developed collectively by the five Trusts, so as to avoid the possibility of children facing a postcode lottery regarding the placements offered to them.