Peishansaurus was named and described by the Swedish paleontologist Anders Birger Bohlin in 1953.

[2] In 1930 Bohlin, in the context of the Swedish-Chinese expeditions of Sven Hedin, had uncovered the fossils at Ehr-chia-wu-t'ung, in the west of Gansu, in a layer of the Minhe Formation dating from the Campanian.

[3] Peishansaurus is today considered a nomen dubium, doubtful genus.

[3] Bohlin placed it in the Ankylosauridae, assuming the fossil represented a juvenile ankylosaurid,[2] but it could also be a pachycephalosaur.

[citation needed] In 1999, Kenneth Carpenter considered the tooth to be similar to that of Psittacosaurus.