Roberto arrived at Bologna in 1977 at 13 and a half years, little more than a child. In 1981, at the age of 16, he was already on the first team and thanks to coach Tarcisio Burgnich he played 30 out of 30 league games, making his Serie A debut against Cagliari.
A month later, Mancini scored his first goal in the Italian Serie A, netting the final 2-2 in Como vs Bologna, the first of nine goals scored in that season which made him the team's best scorer. He left the Rossoblu colors after the 1981/82 season which saw the Felsinei relegated to the Serie B.
