With Fiorentina, Montuori was able to achieve great domestic and international success, as well as international recognition; upon his arrival at the club, he won the only Italian title of his career, during the 1955–56 season, and he followed this triumph with four consecutive second places. He was also able to win the 1960–61 European Cup Winners' Cup, and the 1960–61 Coppa Italia, also reaching the final of the Italian Cup three consecutive times between 1958 and 1960. He also won several minor international trophies with Fiorentina, such as the Grasshoppers Cup in 1957, the Coppa dell'Amicizia twice, in 1959 and 1960, as well as the Coppa delle Alpi in 1960. Montuori's playing career ended prematurely, at the age of 28, in the spring of 1961. During an away friendly match against Perugia, he was hit strongly in the face by the ball, which caused his retina to detach, and his vision to blur, leading him to retire from professional football.