Giaccherini featured 17 times in Serie A last season, contributing four goals and three assists during a campaign in which he played for both Napoli and Chievo.
Napoli's impressive 2017/18 campaign, in which they challenged Juventus for the Serie A title, gave Giaccherini few chances in the first team.
With both Lorenzo Insigne and Jose Callejon ahead of him in the pecking order, Giaccherini made a loan move to Chievo in January. The Italian winger made a very good impression during his time in Verona.
The former Sunderland man has signed a contract that will run until 2021 in a move that makes sense for all parties involved.
Chievo will be hoping that the permanent acquisition of Giaccherini will help them in the goals department next season. The club managed to score just 36 times last season, a total that just five teams did not better.
Napoli, on the other hand, will be looking to once again make a charge for the Serie A title in the 2018/19 season, they may have scored goals for fun last season, but the club will surely be looking to add depth during the transfer window.