Benfica competed domestically in the Primeira Divisão and the Taça de Portugal, and participated in the European Cup after winning the previous league.

After John Mortimore secured the third consecutive league title, Benfica strengthened their squad with Humberto Coelho.

In the league, Benfica campaign started with a draw against Sporting on 3 September, but they won all remaining matches in that month.

[4][5][6] One of biggest sagas of the transfer window was the return of Rui Jordão to Portugal, which Benfica approached to re-sign, but the player refused and insisted on going to rivals Sporting.

[10] The training sessions were mostly spent around Monsanto,[11] and the first preparation game was on 11 August with Portimonense in Estádio do Jamor.

[15] In the European Cup, they progressed to the second round after beating Torpedo Moscow on penalties, with Bento making an important contribution.

[9] In the opening league game of October, Benfica drew in Bessa with Boavista and was caught by Vitória de Guimarães in first, both with 8 points.

[16] Four days later, Benfica met Boldklubben 1903 for the second round of the European Cup, beating them with a goal from Pietra.

[17] Meanwhile, domestically, after the draw in Bessa, Benfica won all remaining league matches in 1977, finishing the year in first with 21 points, four more than Sporting and Porto, who still had a game in hand.

[19] Benfica won the next three matches,[20] one of them a Derby against Sporting with a goal from Vítor Baptista, who subsequently lost an earring, an episode he was best remembered.

Note 2: Players with squad numbers marked ‡ joined the club during the 1977-78 season via transfer, with more details in the following section.