About 250,000 domestic and international travelers are concerned by the walkout of handling and check-in agents scheduled between 10:00 (08:00 GMT) and 18:00 at the call of an inter-union.
They are calling for the signing of a new collective agreement, which expired six years ago.
At Rome's Fiumicino-Leonardo Da Vinci airport, around 200 flights were cancelled, including to Copenhagen, Stockholm, Barcelona or Palma de Mallorca, as well as Palermo or Catania in Sicily.
Malta Air, which operates routes on behalf of Ryanair, Ita Airways (formerly Alitalia), and Vueling whose pilots have decided to join the movement are particularly affected.
Nearly 150 flights were cancelled at the two airports of Milan, Linate and Malpensa, thirty in Turin-Caselle, as many in Palermo.
Transport Minister Matteo Salvini called on the strikers' "common sense" not to prolong their movement and "not to harm millions of other workers and tourists".
© 2023 AFP