As a coach, he led Calabrian third division club Reggina to Serie B in 1988, and then moved to Serie B club Parma. He held that position for six years, leading the Emilian club to its first promotion to the Italian top flight in 1990, and subsequently turned the team into one of the major clubs in the Italian Serie A, thanks also to the relevant financial backing from chairman and Parmalat founder Calisto Tanzi, winning several domestic and European titles. During his time at Parma, Scala won the Coppa Italia in 1992, the Cup Winners' Cup and the European Super Cup in 1993, and the UEFA Cup in 1995. He also managed runners-up medals in the Coppa Italia in 1995, in the Cup Winners' Cup in 1994, and twice in the Supercoppa Italiana in 1992 and 1995, while his best result in the league was a third-place finish during the 1994–95 Serie A season. He left Parma in June 1996.