The class was a part of the Austro-Hungarian Navy's efforts to competitively evaluate three foreign submarine designs.

The two U-3-class boats, both launched in 1908, were just under 140 feet (43 m) long and were each powered by two kerosene two-stroke engines while surfaced, and two electric motors when submerged.

They instead opted to order two submarines each of designs by Simon Lake, Germaniawerft, and John Philip Holland for a competitive evaluation.

[4] The U-3 class was an improved version of Germaniawerft's design for the Imperial German Navy's first U-boat, U-1,[4] and featured a double hull with internal saddle tanks.

[3] From their commissioning to the outbreak of World War I 1914, both U-3-class submarines served as training boats and sailed on as many as ten cruises a month in that capacity.

[5] At the beginning of the war, the U-3 boats made up half of the operational U-boats in the Austro-Hungarian Navy fleet.

[5] In August 1915, U-3 was sunk by a French destroyer after making an unsuccessful torpedo attack on an Italian armed merchant cruiser.

She was commissioned into the Austro-Hungarian Navy on 12 September, and served as a training vessel through the beginning of World War I.

U-3 succumbed to gunfire from the French destroyer Bisson the following day, with the loss of seven crewmen, including Linienschiffsleutnant Karl Strnad, her commanding officer; the other fourteen men of the crew were captured.

She was commissioned into the Austro-Hungarian Navy in August, and served as a training vessel through the beginning of World War I.