Iachini was born in Ascoli Piceno. He started his playing career at Ascoli, and made his Serie A and professional debut during the 1981–82 season, at the age of 17. He played for Ascoli until 1987, when he signed for Verona. 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 Serie C1 season with Alessandria. As a player, he represented the Italy Olympic side at the 1988 Summer Olympics at international level, where they finished in fourth place.
Managerial career
Venezia
Iachini started his coaching career in October 2001, when he was called to coach Venezia of Serie A, despite not being in possession of a coaching license yet. Assisted by "official" head coach Alfredo Magni, Iachini left his position as assistant coach at Piacenza in order to join Venezia, in spite of the Italian football regulation laws, and was successively disqualified for six months because of that. In the end, Venezia were relegated to Serie B.
In the 2003–04 season, Iachini moved at Vicenza, in Serie B, where he managed a team composed mostly by youngsters and led them to a mid-table place.
Piacenza
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.
Chievo Verona: promotion to Serie A
He was announced on June 2007 as new Chievo Verona boss for their 2007–08 Serie B campaign, and successfully led the gialloblu to become league champions and promptly mark their return in the top flight. On 4 November 2008, following an unimpressive start in the 2008–09 Serie A campaign, and two days after a 3–0 loss to Palermo, Iachini was dismissed from his coaching post by the club management.
Brescia: promotion to Serie A
On 4 October 2009, he was appointed new head coach of Serie B outfit Brescia, replacing Alberto Cavasin. Under his tenure, Brescia ended the regular season in third place, missing automatic promotion in the final game of the season. The team however went back to win the promotion playoffs and claim a place in the 2010–11 Serie A after defeating Torino F.C. in the finals. After a wave of bad results, resulting on the team's dropdown to the relegation zone near the winter, on 6 December 2010, he was sacked; However, he was called back at the helm of Brescia boss less than two months later, following the dismissal of his successor Mario Beretta on 30 January 2011.
Sampdoria: promotion to Serie A
On 14 November 2011, Iachini was named as the new head coach of Sampdoria, after a disastrous start to the season in Serie B, in place of the sacked Gianluca Atzori. He charged the team, strongly depressed under the psychological profile and in winter market with radically revised to players motivated and adapted to the category. On 9 June 2012 the team, ranked only 6th in the league with an incredible recover, was promoted after playoffs to Serie A defeating Varese in the finals.
On 17 December 2012, Iachini was appointed the new coach of Siena in Serie A en place of the sacked Serse Cosmi. He left the club by the end of the season.
Palermo
On 25 September 2013, he was announced as new head coach of Palermo, a former team of his as a player, signing a two-year contract and taking over from dismissed Gennaro Gattuso. During his tenure, he succeeded in turning the Sicilians' fortunes and won his personal fourth top flight promotion, guiding Palermo to be crowned Serie B champions on the 3rd of May, five matches before the end of season. He was successively confirmed as Palermo head coach for the upcoming 2014–15 Serie A season. He was sacked on 10 November 2015. Following a confusing period where Palermo owner Maurizio Zamparini appointed four different managers in a month after the sacking of Davide Ballardini, Iachini returned as manager of the club on 15 February 2016, but was sacked once again on 10 March.
On 27 November 2017, Iachini was named manager of Sassuolo following the sacking of Christian Bucchi. He left the club on 5 June 2018 by mutual consent.
