2012 Tercera División play-offs

The eighteen group winners have the opportunity to be promoted directly to Segunda División B. The eighteen group winners were drawn into a two-legged series where the nine winners will promote to Segunda División B. The nine losing clubs will enter the play-off round for the last nine promotion spots.

The eighteen runners-up were drawn against one of the seventeen fourth-placed clubs outside their group and the eighteen third-placed clubs were drawn against one another in a two-legged series. The twenty-seven winners will advance with the nine losing clubs from the champions' series to determine the eighteen teams that will enter the last two-legged series for the last nine promotion spots. In all the playoff series, the lower-ranked club play at home first. Whenever there is a tie in position (e.g. like the group winners in the champions' series or the third-placed teams in the first round), a draw determines the club to play at home first.