On 30 June 2007, Gargano agreed a transfer from Uruguayan club Danubio to newly promoted Napoli for a fee of £2m signing a five-year contract. He made his first appearance for the club in a 4–0 win over Cesena and made his Serie A debut on 26 August 2007 against Cagliari. On 20 October 2007, he scored his first goal in a 4–4 draw against Roma and netted the following week, in a 3–1 win over Juventus. In his first season, he made 34 appearance scoring twice. Also during his first season, Gargano received two sending offs, a second bookable offence in a 5–2 loss against Milan on 13 January 2008 and three months on, a straight red card in a 2–1 win over Parma on 20 April 2008.