The Astra 900 was a pistol developed to take advantage of a large Chinese demand for semiauto pistols with shoulder stocks, following on the massive sales of the Mauser C96 "Broomhandle" in that country. In the 1920s and 30s, civil war in China drove a huge market in arms, but international treaty had prohibited the importation of military arms. One loophole in the accords, however, was that stocked pistols (including fully automatic stocked pistols) were not considered military arms.

Mauser led the sales to China, but several Spanish companies jumped into the market as well, and the Astra 900 was a well made and reasonably popular gun.The semiauto 900 was chambered for 7.63mm Mauser (like the C96), and about 21,000 were made from 1928 into the 1930s. A series of improved designs followed, with the 901 (select-fire), 902 (select-fire with a fixed 20-round magazine), 903 (select-fire with detachable magazines), and 904/Model F (select-fire with detachable magazines and a rate-reducing mechanism).