Gretna, LA -- U.S. city in Louisiana Population (2000): 17423 Housing Units (2000): 7665 Land area (2000): 3.495891 sq. miles (9.054317 sq. km) Water area (2000): 0.363682 sq. miles (0.941933 sq. km) Total area (2000): 3.859573 sq. miles (9.996250 sq. km) FIPS code: 31915 Located within: Louisiana (LA), FIPS 22 Location: 29.916459 N, 90.054260 W ZIP Codes (1990): 70053 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Gretna, LA Gretna