Benfica competed domestically in the Primeira Divisão and the Taça de Portugal, and participated in the UEFA Cup after finishing second in the previous league.

[3] The season brought significant changes because it was the first time that the club signed foreign players, after a members meet on 1 July 1978 decided to remove that prerequisite.

[12] The pre-season began on 23 July, and their opening game was on a tournament celebrating the 75 years of Schalke 04, which also included Liverpool.

[18] On the league, Benfica dropped to second after a draw with União de Leiria,[19] but managed to recover and catch Porto on match-day 8.

[20] The next week, Benfica lost with Varzim, losing the first place and also Chalana who had a serious injury; they conceded their second loss in a row in the reception to Boavista on match-day 11, dropping to third, four points from the leader.

[23] Two weeks later, in the visit to Estádio das Antas to face Porto, Benfica lost 2–1 and opened a four-point deficit, which Wilson admitted: "is a disadvantage difficult to overcome".

[26] On 13 April, Benfica visited Estádio de Alvalade to play Sporting, losing 3–1, with the gap to the leader Porto now at six points.

[1] On 7 June, in the Taça de Portugal final in a sold-out stadium, Benfica beat Porto by 1–0 with a goal from César.

Note 2: Players with squad numbers marked ‡ joined the club during the 1979-80 season via transfer, with more details in the following section.