2005 Segunda División B play-offs

The 2005 Segunda División B play-offs (Playoffs de Ascenso or Promoción de Ascenso) were the final playoffs for promotion from 2004–05 Segunda División B to the 2005–06 Segunda División. The four first placed teams in each of the four Segunda División B groups played the Playoffs de Ascenso and the four last placed teams in Segunda División were relegated to Segunda División B.

Teams for 2004/2005 play-off

 * RSD Alcalá
 * SD Ponferradina
 * AD Ceuta
 * Hércules CF
 * Sevilla B
 * Zamora CF
 * CD Castellón
 * Universidad de Las Palmas CF
 * Alicante CF
 * Rayo Vallecano
 * Real Zaragoza B
 * Lorca Deportiva CF
 * Real Unión
 * Burgos CF
 * UB Conquense
 * Real Madrid B

Second round
 Group A--Second Eliminatory Promoted to Segunda División: Hércules CF
 * Home Match
 * Away Match

Group B--Second Eliminatory Promoted to Segunda División: CD Castellón
 * Home Match
 * Away Match

Group C--Second Eliminatory Promoted to Segunda División: Lorca Deportiva CF
 * Home Match
 * Away Match

Group D--Second Eliminatory Promoted to Segunda División: Real Madrid B 
 * Home Match
 * Away Match