This article presents some of the key findings of a Regional Studies Association funded project on internal migration in Europe (“Understanding the declining trend in internal migration in Europe”). The project aims to examine the long-term trend of migration rates in 27 European countries. Specifically, two of the key aims are: (1) to assess the prevalence of migration decline in Europe; and, (2) to establish the start and pace of this contemporary trend. The current article will present some key findings and provide some details of the complexities in terms of spatial and temporal data harmonisation for the analysis of internal migration trends.