The 26-year-old spent five season in the Italian capital but, after the Old Lady activated his 32m euros release clause, he moved to Turin on a five-year deal.
The Bosnia midfielder has scored one goal from five Serie A outings to date, with Juve in their customary position at the top of the Italian top-flight table.
Despite being an influential member of the Roma side, Pjanic won nothing while at the Stadio Olimpico and is now keen to put that right with his new club.
"I’m at Juve to win titles," he told France Football. "That’s what I’m most lacking, and Juventus is the perfect club to do that, there’s a winning culture on every level. Up until now I’ve often been second.
"Juve have a consistency of performance that we definitely didn’t have at Roma, we always had ups and downs."