Throughout the season many Premier League, Super League, Division One and Division Two teams competed in a newly formed FA Cup-style knockout competition called the Statewide Cup in which the Sydney United were crowned champions after defeating Belconnen Blue Devils in 3–1 at Parramatta Stadium.
Manly United were also promoted from the NSW Super League.
The first stage consisted of fifteen rounds with each of the sixteen teams playing each other once.
[2] Teams relegated from National Soccer League: (After the end of the 2003–04 season) Teams promoted from Super League: (After the end of the 2004 season.)
Teams relegated to Super League: (After the end of the 2003–04 season.)