(1,930 km?) 123 sq mi (319 km?), 14.18% Population - ( 2006 ) - Density 450,171 464/sq mi (179/km?) Website: www.pascocountyfl.net Pasco County is a county located in the U.S. state of Florida . As of 2000 , the population was 344,765. The 2006 census estimate according to the U.S. Census