Trouser laser treatment device and corresponding trouser holder. Trouser laser treatment device comprising [a] a trouser supply module 1 comprising transport 3 for transporting each of the trousers from an entry to a supply exit 4, [b] an opening module 14 of the waist of one of the trousers, arranged in the supply exit 4, and [c] a transport module 5 with fastening clamps 7 that hold the trousers with the waist open by the waist and that carries the trousers from the supply exit 4 to a trouser holder 9 of a work station 8 with a laser device and a rotation means 26 able to rotate the trouser holder 9 according to a vertical axis. The trouser holder 9 comprises, on each leg, an outer rod 28 and an inner rod 29, which deploy sideways, and a third rod 31, arranged between the other two, which is deployed forward or backward.