The 2005–06 season in Portuguese football saw Porto, led by Co Adriaanse, clinch their 21st title and win the Taça de Portugal.
Benfica had a disappointing season, although they returned to the spotlight of European football with a good run in the Champions League, reaching the quarter-finals.
Braga and Nacional challenged Sporting CP, Benfica and Porto for a major part of the season.
Also of note was the suspension of Benfica midfielder Nuno Assis after testing positive for a banned substance in a league match [1].
In international football, the Portugal national team secured a place in Germany's 2006 FIFA World Cup, where they were grouped alongside Mexico, Iran and newcomer Angola.
Because the Portuguese system doesn't apply the away goal rule, the teams went to penalties, in which Madalena won 5-4.