In 1989, Iachini moved to Fiorentina and played five seasons with the viola, four of them in Serie A. From 1994 to 1996 he played for Palermo of Serie B. After a single Serie B season with Ravenna, in 1997 Iachini transferred to Venezia, where he played for three years, two of them in Serie A. He retired in 2001, after a SINGLE Serie C1 season with Alessandria.
In 2002–2003, Iachini coached Cesena of Serie C1, leading his team to a spot in the promotion playoffs. In 2003–2004, Iachini moved at Vicenza, in Serie B, where he managed a team composed mostly by youngsters and led them to a mid-table place. He coached Piacenza, another Serie B club, from 2004–05 to 2006–07 with good results, including a notable fourth place, only behind Juventus, Napoli and Genoa, in his latest season with the biancorossi. He was announced on June 2007 as new ChievoVerona boss for their 2007–08 Serie B campaign. In this year the team returns in serie A.