It was the last regionalized contest for the second tier championship, as a new Segunda Liga took shape as an unified second tier from the next season onwards.
[1] The league was contested by 54 teams in 3 divisions with SC Salgueiros, Gil Vicente FC and SC Farense winning the respective divisional competitions and gaining promotion to the Primeira Liga.
The overall championship was won by SC Salgueiros.
[1] The last 4 classified in each series competed for against the teams classified in 6th place in each of the 6 series of the III Divisão and the 2 best 7th classified of the 6 series of the III Divisão (CD Fátima and Moura), in one hand.
The 10 winners qualified for 1990–91 Segunda Divisão B, while the losers competed in 1990–91 Terceira Divisão.