The 2012–13 Argentine Primera B Nacional was the 27th season of second division professional of football in Argentina.
A total of 20 teams competed; the champion, runner-up and third-placed team were promoted to Argentine Primera División.
Clubs with an indirect affiliation with Argentine Football Association are relegated to the Torneo Argentino A, while clubs directly affiliated face relegation to Primera B Metropolitana.
Clubs with direct affiliation are all from Greater Buenos Aires, with the exception of Rosario Central, Newell's Old Boys, Central Córdoba and Argentino de Rosario, all from Rosario, and Unión and Colón from Santa Fe.
The bottom two teams of this table face relegation regardless of their affiliation status.