District 9 opened in 3,049 theaters in the United States and Canada on August 14, 2009, and the film ranked first at the weekend box office with an opening gross of $37,354,308.
Among comparable science fiction films in the past, its opening attendance was slightly less than the 2008 film Cloverfield and the 1997 film Starship Troopers. The audience demographic for District 9 was 64 percent male and 57 percent people 25 years or older.The film stood out as a summer film that generated strong business despite little-known casting.Its opening success was attributed to the studio's unusual marketing campaign. In the film's second weekend, it dropped 49% in revenue competing against the opening film Inglourious Basterds for the male audience, and Sony Pictures attributed the "good hold" to District 9's strong playability.The film enjoyed similar success in the UK with an opening gross of £2,288,378 (447 screens) making it the highest grossing film of the weekend ending September 6, 2009. As of September 7, 2009, it has grossed an estimated $103,274,000 in the United States and Canada and $14,336,708 in other territories for a worldwide total of $117,610,708.
