2005 Segunda División B play-offs
First round
| June 5, 2005
Home Matches: | |||
| RSD Alcalá | 1-1 | SD Ponferradina | |
| AD Ceuta | 0-1 | Hercules CF | |
| Zamora CF | 0-0 | Sevilla FC B | |
| CD Castellon | 0-0 | Universidad de Las Palmas CF | |
| Lorca Deportiva | 1-0 | Alicante CF | |
| Rayo Vallecano | 1-1 | Real Unión | |
| Real Zaragoza B | 0-0 | Real Madrid B | |
| Burgos CF | 0-0 | UB Conquense |
| June 12, 2005
Away Matches: | |||
| SD Ponferradina | 0-1 | RSD Alcalá | Agg:1-2 |
| Hercules CF | 2-0 | AD Ceuta | Agg:3-0 |
| Sevilla FC B | 1-1 | Zamora CF | Agg:1-1 |
| Universidad de Las Palmas CF | 1-2 | CD Castellon | Agg:1-2 |
| Alicante CF | 1-2 | Lorca Deportiva | Agg:1-3 |
| Real Unión | 1-0 | Rayo Vallecano | Agg:2-1 |
| Real Madrid B | 2-0 | Real Zaragoza B | Agg:2-0 |
| UB Conquense | 1-0 | Burgos CF | Agg:1-0 |
Second round
Group A--Second Eliminatory
- Home Match18-Jun-2005-RSD Alcalá 1-3 Hercules CF-Stadium:Virgen del Val (Alcalá de Henares)
- Away Match26-Jun-2005-Hercules CF 1-1 RSD Alcalá-Stadium:José Rico Pérez (Alicante)
Promoted to Segunda División: Hercules CF
Group B--Second Eliminatory
- Home Match19-Jun-2005-Zamora CF 2-1 CD Castellón-Stadium:Virgen del Val (Zamora)
- Away Match26-Jun-2005-CD Castellón 1-0 Zamora CF-Stadium:Ruta de la Plata (Castellón)
Promoted to Segunda División: CD Castellon
Group C--Second Eliminatory
- Home Match19-Jun-2005-Lorca CF 1-2 Real Unión-Stadium:Francisco Artes Carrasco (Lorca)
- Away Match26-Jun-2005-Real Unión 1-3 Lorca FC-Stadium:Stadium Gal (Irún)
Promoted to Segunda División: Lorca FC
Group D--Second Eliminatory
- Home Match18-Jun-2005-UB Conquense 0-2 Real Madrid B -Stadium:La Fuensanta (Cuenca)
- Away Match26-Jun-2005-Real Madrid B 0-1 UB Conquense-Stadium:Santiago Bernabeu (Madrid)
Promoted to Segunda División: Real Madrid B