2004 Segunda División B play-offs

The 2004 Segunda División B play-offs (Playoffs de Ascenso or Promoción de Ascenso) were the final playoffs for promotion from 2003–04 Segunda División B to the 2004–05 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.

The teams play a league of four teams, divided into 4 groups. The champion of each group is promoted to Segunda División.