| Competition: | Primera B Nacional |
| Season: | 2012–13 |
| Winners: | Rosario Central (1st divisional title) |
| Promoted: | Rosario Central Gimnasia y Esgrima (LP) Olimpo |
| Relegated: | Deportivo Merlo Nueva Chicago |
| League Topscorer: | Luis Rodriguez 20 goals |
| Matches: | 380 |
| Total Goals: | 775 |
| Prevseason: | 2011–12 |
| Nextseason: | 2013–14 |
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.
| width=28 | width=185 | Team | width=50 | width=50 | width=50 | width=50 | width=50 | width=50 | Relegation | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Olimpo | — | — | 66 | 66 | 38 | Indirect | ||||||||||
| 2 | Rosario Central | 50 | 69 | 74 | 193 | 114 | Direct | ||||||||||
| 3 | Gimnasia y Esgrima (LP) | — | 54 | 73 | 127 | 76 | Direct | ||||||||||
| 4 | Sarmiento (J) | — | — | 58 | 58 | 38 | Direct | ||||||||||
| 5 | Banfield | — | — | 58 | 58 | 38 | Direct | ||||||||||
| 6 | Patronato | 50 | 56 | 56 | 162 | 114 | Indirect | ||||||||||
| 7 | Instituto | 51 | 70 | 39 | 160 | 114 | Indirect | ||||||||||
| 8 | Defensa y Justicia | 43 | 54 | 57 | 154 | 114 | Direct | ||||||||||
| 9 | Boca Unidos | 52 | 57 | 45 | 154 | 114 | Indirect | ||||||||||
| 10 | Almirante Brown | 52 | 55 | 46 | 153 | 114 | Direct | ||||||||||
| 11 | Huracán | — | 46 | 54 | 100 | 76 | Direct | ||||||||||
| 12 | Aldosivi | 52 | 53 | 44 | 149 | 114 | Indirect | ||||||||||
| 13 | Douglas Haig | — | — | 49 | 49 | 38 | Indirect | ||||||||||
| 14 | Ferro Carril Oeste | 47 | 56 | 43 | 146 | 114 | Direct | ||||||||||
| 15 | Atlético Tucumán | 51 | 42 | 51 | 144 | 114 | Indirect | ||||||||||
| 16 | Gimnasia y Esgrima (J) | 54 | 34 | 50 | 138 | 114 | Indirect | ||||||||||
| 17 | Crucero del Norte | — | — | 45 | 45 | 38 | Indirect | ||||||||||
| 18 | Independiente Rivadavia | 40 | 45 | 48 | 133 | 114 | Indirect | ||||||||||
| 19 | Deportivo Merlo (R) | 51 | 43 | 37 | 131 | 114 | Primera B Metropolitana | Direct | |||||||||
| 20 | Nueva Chicago (R) | — | — | 31 | 31 | 38 | Primera B Metropolitana | Direct |
| Rank | Player | Club | Goals[1] | |
|---|---|---|---|---|
| 1 |  Luis Rodriguez | Atlético Tucumán | 20 | |
| 2 | Facundo Pereyra | Gimnasia y Esgrima (LP) | 15 | |
| Andrés Chávez | Banfield | |||
| Cristian Milla | Defensa y Justicia | |||
| 5 | Pablo Mazza | Douglas Haig | 12 | |
| Jeronimo Barrales | Huracán | |||
| Cristian Chávez | Almirante Brown | |||
| 8 | Mauricio Carrasco | Patronato | 11 | |
| 9 | Javier Toledo | Rosario Central | 10 |