1989–90 Terceira Divisão

The league was contested by 108 teams distributed across 6 groups of 18 teams each. A.D. Esposende, A.D. Lousada, Anadia F.C., U.F.C.I. Tomar, C.D. Santa Clara, and C.D. Montijo won their respective groups and advanced to the Championship play-off. C.D. Montijo was the overall champion after defeating A.D. Lousada 1–0 in the Championship final. ==League standings==

Terceira Divisão – Group 1 Terceira Divisão – Group 2 Terceira Divisão – Group 3 Terceira Divisão – Group 4 Terceira Divisão – Group 5 Terceira Divisão – Group 6 ==Championship play-off==

Championship play-off – Zone 1 Championship play-off – Zone 2 Championship final ==Segunda Divisão B play-off==

The Segunda Divisão B play-off was a single-match series featuring the four lowest-placed teams from each group of the second-tier Segunda Divisão (2D), the six 6th-placed teams from each of the six series of the third-tier Terceira Divisão, and the two best 7th-placed teams from across the six Terceira Divisão series. The 10 winners qualified to third-tier 1990–91 Segunda Divisão B, while the losing sides moved to fourth-tier 1990–91 Terceira Divisão. ==Relegation play-off==

The Relegation play-off was a two-round series, each with a single-match, featuring the four lowest-placed teams from each group of the third-tier Terceira Divisão, and 12 teams from the fourth-tier District Championships (D). The 9 winners from Second round qualified to fourth-tier 1990–91 Terceira Divisão, while the losing sides from both rounds were relegated to the fifth-tier 1990–91 District Championships. First round Second round ==Footnotes==