The 2004–05 Argentine Torneo Argentino A[1] was the tenth season of third division professional football in Argentina.
A total of 20 teams competed; the champion was promoted to Primera B Nacional.
In every round the bye team played against the bye team of the other zone: Team from Zone A vs Team from Zone B and Team from Zone C vs Team from Zone D. In every round the bye team played against the bye team of the other zone: Team from Zone A vs Team from Zone B and Team from Zone C vs Team from Zone D. 1: First leg awarded 0-1; originally 3-0 but Real Arroyo Seco used ineligible players.