Mehdishahr DistrictMehdishahr District is a former administrative division of Semnan County, Semnan province, Iran. Its capital was the city of Mehdishahr.HistoryIn 2007, the district was separated from the county in the establishment of Mehdishahr County.DemographicsPopulationAt the time of the 2006 National Census, the district's population was 36,093 in 9,573 households.