Later, having the Italian Army judged the 7.65 round to be too light for military use, and having launched a competition for 9mm handguns instead, the Metallurgica Bresciana Tampini, owner of the design, adapted the Glisenti pistol to fire a 9mm round, obtained enlarging the original one (eliminating the bottleneck) without changing the load.

The chief designer Tullio Marengoni completed his design of a simple blowback action pistol that could fire the same 9mm Glisenti cartridge, was patented by the Pietro Beretta Arms Factory on June 29, 1915, and was immediately adopted by the Royal Army, just over a month involved in the Great War.

A .32 ACP version, the Beretta M1917, was also produced and was adopted by the Italian Royal Navy.

In the 9mm Glisenti model, the barrel is exposed by an open slide - the signature design for later Beretta pistols but unlike later Beretta pistols, the front sight is fitted along the front end of the barrel as that part of the slide is cut open.

The straight handle, inclined only 9 ° with respect to the barrel, has vertically scored grip panels instead of knurled ones.

The frame mounted safety one on the left side is present as well as acting as a safe blocking the trigger, it also works as a dismounting pin and hold open lever .