During the past several decades, many studies illustrated the importance of socioeconomic factors on interregional migration in different countries. Interregional migration has had an immense impact on Turkey's population dynamics after the 1950s. This study aims at investigating the patterns of interregional migration in Turkey during the period of 2008 to 2010 using a hierarchical cluster analysis. First, the paper gives background information about interregional migration by providing the ratios of immigration and emigration with respect to the population and the characteristics of the regions between 2007 and 2010. Second, interregional immigration and emigration flows are investigated by the use of a hierarchical clustering analysis with different linkage techniques, e.g., single, complete, average, and others, which determine how the distance between two clusters should be defined to represent actual partitioning. Then, the best partitioning of the regions is selected based on a popular internal or unsupervised criterion, called cophenetic correlation. According to the results obtained by the single linkage that yielded the highest cophenetic correlation, the country's largest city, Istanbul, dominates the largest cluster of the country consisting of the regions from east to west both immigration and emigration flows. These analyses have shed light on the complex relationship of the interregional migration in Turkey. Regional inequalities can be overcome first by understanding this complex relationship of the interregional migration in the country. Then, under a national strategic development plan, public investments can be directed more to, and private investments can be encouraged in, underdeveloped regions via the tool of economic subsidies in order to create economic sustainability across the regions throughout the country. (C) 2014 American Society of Civil Engineers.