On 29 January 2010 he was appointed to replace Ciro Ferrara as head coach of under-crisis Juventus. He signed a four-month contract. On 14 February 2010, Zaccheroni achieved his first win as a Juventus manager, defeating Genoa 3–2. His first loss in charge of the team arrived two weeks later, a 0–2 home defeat to Palermo.
On 30 August 2010, it was revealed via an announcement from the Japan Football Association that Zaccheroni would become the new manager of the Japan national football team. However, due to a visa problem, he was not able to take charge in the first two matches against Paraguay (1–0) and Guatemala (2–1), in which former Japan striker and JFA technical director Hiromi Hara took charge. The first match he took charge, Japan had a historic 1–0 win over Argentina.