On 14 June 1940, four days after Italy's entry into the war, the French heavy cruisers Dupleix and Colbert with destroyers Albatros and Vautour sortied from Toulon and shelled Genoa's industrial zone, between Sestri Ponente and Arenzano (at the same time, another French naval formation attacked the industrial plants of Savona and Vado Ligure).

Only one third of the shells fired hit the targets; industrial plants did not suffer heavy damage, and the only two warships undergoing work in the shipyards, the battleship Duilio and the destroyer Bersagliere, remained unscathed.

The city instead suffered serious damage, with the destruction of 250 buildings, 144 dead and 272 wounded among the civilian population, and 2,500 people left homeless.

Two British bombers, part of a group of 36 that had taken off from bases in England (another two were lost), dropped five tons of bombs, causing little damage and few casualties.

[5] Eight Vickers Wellington bombers from Haddock Force, based in Provence, attacked the Ansaldo shipyards and the Piaggio plants.

[11] Raid by eighteen Bomber Command aircraft (many of which failed to reach Genoa and attacked Savona and Imperia instead), which dropped 9.5 tons of bombs.

The old city centre, the harbour, the shipyards, and the eastern suburbs were hit; among the damaged buildings were the Genova Brignole railway station, the Pammatone hospital, the churches of Santa Maria in Passione and Sant'Agostino, the medieval "portico" of Sottoripa, Palazzo Spinola, Palazzo San Giorgio and the Doge's Palace.

Bad weather dispersed many of the 122 bombers that had originally taken off from England (three of which were lost), with many erroneously attacking Savona (mistaken for Genoa), killing 55 people, Vado Ligure or Turin; in Genoa, material damage was relatively light (among the damaged buildings were the Basilica of the Santissima Annunziata, the Gio Vincenzo Imperiale Palace and the Paganini Theatre, which was destroyed and never rebuilt), to the point that the Bomber Command considered this raid a failure (unlike the previous and following ones, all of which were considered as successful and well concentrated)[16] The panic caused by the previous night's attack caused a mass stampede at the entrance of an air raid shelter near Porta Soprana, in which at least 354 people (according to the official toll; others estimate 500) lost their lives.

The central and eastern districts were hit, with damage to the church of San Donato and to Villa Pallavicini; twenty civilians were killed.

The shipyard and the eastern districts were hit, with damage to the basilica of the Santissima Annunziata, to Sottoripa, and to Doria, Spinola, Arcivescovile and Accademia Ligustica palaces.

Both the Ansaldo and the city were targeted; both were hit, with damage to the Sampierdarena marshalling yard, the Brignole district, the Galliera hospital, the Basilica of San Siro, the church of Santo Stefano, the Spinola and Accademia Ligustica palaces, the Loggia della Mercanzia.

Civilian casualties (451 deaths) were relatively light when compared to the extent of the damage; this was largely due to the greater availability (both in number and capacity) of air raid shelters in Genoa, many of which were located in tunnels and underground passages, without buildings that could collapse and bury them (one of the main causes of death in air raids).

[35] 133 bombers of the 12th U.S. Air Force attacked the marshalling yard and the Ansaldo, hitting both the targets and the city, killing about sixty people The Vigili del Fuoco (fire brigade) managed to save another thirty-people from under the rubble)and causing serious damage to the water and gas networks.

The bombs fell on Sestri, Pegli, Rivarolo, Sampierdarena and Cornigliano, killing sixteen civilians and wounding about twenty.

497 tons of bombs were dropped, hitting both the target and the city (especially the Voltri, Rivarolo, Cornigliano and Sampierdarena districts), causing 93 dead and 130 wounded.

[65] B-24 bombers of the 15th Air Force dropped 58,5 tons of bombs on the harbour, sinking the incomplete Capitani Romani-class cruiser Cornelio Silla but also hitting the city centre.

[68][69][70] North American B-25 Mitchell and Martin B-26 Marauder medium bombers of the 12th Air Force attacked the port facilities and the road network.

[71] USAAF aircraft launched a series of attacks on coastal batteries in and around Genoa, in preparation for the landings in Southern France.

[72] 59 RAF bombers attacked the harbour, but also hit the city (the Palazzo Reale and the basilica of San Siro, among other things, suffered damage).

[82] In the closing days of the war, further damage to port facilities was caused by German troops, who blew up large sections of the breakwater, disabled dry docks, wrecked machinery, laid 140 mines in the harbour and scuttled dozens of vessels as blockships (by the end of the war, as many as 935 wrecks – 320 ships and 615 smaller craft and floating objects – lay in the harbour, part of them sunk by the air raids, part scuttled by the Germans).