The following season, Gargano was linked with a move while the arrival of Gökhan Inler from Udinese threatened his first-team place. Eventually, he remained at the club. Having placed third in the league the previous, the club entered the Champions League. He made his debut in the Champions League in a 1–1 draw against Manchester City and played all seven matches, with Napoli progressing through the knockout stage before being eliminated by Chelsea. Gargano was involved in the squad assisting a goal for Edinson Cavani, who scored a hat-trick in a 3–1 win over defending champions Milan. On 21 December 2011, he scored his first goal in a 6–1 win against Genoa, ending his four-year goal drought. Three months later, on 9 March 2012, he scored his second of the season in a 6–3 win over Cagliari. At the end of the season, Napoli won the Coppa Italia final in a 2–0 win over Juventus in which Gargano did not feature after picking up his second yellow card in the semi final match against Siena.