Surprise is a city in Maricopa County, Arizona, USA. The population was 30,848 at the 2000 census; however, rapid growth has boosted the city's population to 90,717 by 2007, according to Census Bureau estimates. As such, it is the second fastest-growing municipality in the greater Phoenix metropolitan area, and between 1990 and 2000, it was the sixth fastest-growing place among all cities and towns in Arizona. An estimate released by the city's Demographic and Permit Statistics department showed a population of 109,672 in December 2008.