The Fiorentina Supporters Association (ATF) boycotted the opening 45 minutes of Sunday's goalless home draw with Bologna in protest against the club's ownership.
Brothers Andrea and Diego Della Valle, who are billionaires through their luxury shoe company Tod's, bought the club in 2002 after it had been declared bankrupt and relegated to Italy's fourth tier. However, ATF has accused the owners of failing to invest since then and made its feelings known.
Fans spent the first half inside the stadium in the zone below the seating area but came back out for the second half.
"We have registered a single, united front -- critical of an ownership guilty of having abandoned our beloved Fiorentina for years," a statement posted on the group's official Facebook page on Thursday read. "The next concrete move Fiorentina's organised fanbase will make is to leave seats empty during the opening 45 minutes of Sunday's match against Bologna.
"[This is] a sign of the broken relationship with the Della Valle brothers which will certainly not go unnoticed. We invite everyone who has chosen for some time to protest by join us in buying a ticket and leaving the stadium deserted.
"It will be an important moment which will set in motion a series of initiatives -- therefore your presence is fundamental. In the second half, fans will go back up to their seats to support the guys on the pitch -- for the shirt and for who still believes.
"ATF and all the organisations involved will look at new forms of protest to put in motion -- this is only the beginning. For Florence, for Fiorentina fans."
ESPN FC has contacted Fiorentina for comment.
Fiorentina recently hired Vincenzo Montella as manager following the resignation of Stefano Pioli.