Asamoah and Udinese teammate Mauricio Isla both joined Juventus in July 2012 on co-ownership agreements, with Juventus paying €9 million for 50% of Asamoah's contract. He made his debut on 11 August 2012 against Napoli in the 2012 Supercoppa Italiana, scoring a goal as Juventus went on to win 4–2 after extra time. Due to his impressive performance against Napoli, Antonio Conte, who was Juventus's coach at the time, decided to start him in the opening league match of the 2012–13 season, against Parma, on 25 August: he made an immediate impact, by setting up Stephan Lichtsteiner's goal in a 2–0 home win. On 16 September, he scored his first goal with his new club in a 3–1 away league win over Genoa. Juventus went on to win the Serie A title that season. Asamoah was bought outright by Juventus in June 2013, signing a four-year deal with the club.