Fiorentina, winless and last in Serie A, rehired Paolo Vanoli on Monday to replace Fabio Grosso, who was sacked after losing his first three matches.
"Fiorentina announces that Paolo Vanoli has been appointed as head coach of the first team," said a club statement.
Last November with the club bottom of Serie A, Vanoli, who has also managed Venezia and Torino, took over as Fiorentina's third coach of the season.
He eventually guided them to safety and was initially due to extend his contract by one season.
Instead Fiorentina's board in June handed the team to former World Cup winner Grosso, who was then in charge at Sassuolo.
"We would like to thank Vanoli for the enthusiasm with which he immediately accepted the chance to take charge of the team once again," said the club's statement Monday.
Fiorentina who are celebrating their centenary this year spent more heavily than usual in the summer but have started their season scoring just one goal in three league games.
