The Campeonato Argentino de Rugby 1999 was based on the selection of the Argentine Rugby Union (Unione di Buenos Aires).
The 21 teams participating were divided into three levels : "Campeonato", "Ascenso", "Promocional".
There were no relegation due to the return to an "eight teams formula" per 2000.
Because of the restructuring of the championship, both teams were promoted.