Depopulation is a severe problem in many urban areas globally. Massive population migrations can occur due to relocation after natural disasters and significantly change the demographic composition of regions and cities. The 2011 Great Tsunami in Japan resulted in a combined total of deaths and missing persons of more than 24,500. Post-tsunami recovery efforts resulted in widespread population relocation of high-risk communities into lower-risk areas. Using the Fukushima Prefecture in Japan as the study area, a region characterized by several depopulating cities both pre and post-tsunami, this research examines how the population relocation efforts have either exacerbated or assisted in lessening the effects of urban shrinkage and decline after the earthquake and tsunami of 2011. The results show that 30 municipalities have seen population and economic growth since 2011, and 12 municipalities are underdoing trends toward decline within Fukushima. Negatively affected cities tend to have larger populations than positively affected cities. Most of the small towns and villages closer to the inundation area are fall into the category of negatively affected areas. Moreover, the population increases in many post-disaster cities are primarily due to significant increases in elderly populations with minimal young persons that will inevitably decline in the next decade. By determining the effects of their relocation efforts, the government can better develop targeted strategies that good for the prosperity and development of the Fukushima Prefecture.