In eight wartime patrols she sank 40 ships totaling 72,817 gross register tons (GRT) and one escort.

Like all Type UB III submarines, UB-49 carried 10 torpedoes and was armed with an 8.8 centimetres (3.5 in) deck gun.

[3] On 22 August 1917, UB-49 left Kiel for Cattaro to join the Pola Flotilla passing the Orkney-Shetland barrier four days later.

While Spanish authorities planned to intern UB-49 for the duration of the war, her crew managed to repair the damage to the fuel tanks and bunker enough oil to reach Cattaro.

The next day, two Italian sailing ships were sunk, while exchanging fire with a coastal battery at the same time.

On the way back to Cattaro, UB-49 experienced problems with her ballast tanks east of Malta and dived uncontrolled to a depth of 67 metres (220 ft).

Using compressed air to blow out all ballast tanks simultaneously, UB-49 was able to surface again and continue her journey to Cattaro.

From 13 March 1918 UB-49 pursued a convoy leaving Genoa for Naples and in two days managed to sink three out of four steamers.

Between 19 and 21 March 1918, UB-49 operated in the Gulf of Naples, sinking several Italian sailing ships and shelling the fortifications of Civitavecchia.

In the last week of May, UB-49 successfully attacked Allied shipping south of the Balearic Islands, sinking three steamers.