Perugia sacked coach Daniel Castellani and replaced him with its former mentor.
Perugia confirmed the news on Wednesday, less than 24 hours after the 3-0 victory over LPR Volley Piacenza.
Club president Gino Sirci thanked Castellani for his service in a statement published on the club’s website.
Kovac returns to the club he helped take to the top of Serie A in a hugely succcessful stint from 2011-2014.
He was sacked by Iran Volleyball Federation last month after an unsuccessful two-year term in charge of the men’s national team.
“Boban is a coach who has left a great mark on all of us and with whom we were all on good terms,” Sirci said.
“This opportunity presented itself and we decided to grab it.
“We are talking about one of the best coaches around and I’m confident with his character and knowledge he can get the best out of our players,” he added.