During the Second World War Hyacinth served in the Eastern Mediterranean where she protected the Palestine coastline and escorted numerous convoys along it.

She was a part of the 10th Corvette Group of the Mediterranean Fleet based in Alexandria together with her sister ships Peony and Salvia.

Since Hyacinth spent most of her time in the Mediterranean, without access to British shipyards, she was not retrofitted as many of her class were, and so retained her short forecastle.

[2] On 28 September 1941, Hyacinth attacked and sank the Italian submarine Fisalia north-west of the port of Jaffa, at 32º19'N, 34º17'E, just off the beach at Tel Aviv.

On 9 July 1942, while escorting a convoy from Jaffa to Beirut Hyacinth attacked, damaged and captured the Italian submarine Perla.