The ATLAS trigger system is responsible for selecting the interesting collision events delivered by the Large Hadron Collider(LHC). The ATLAS trigger will need to achieve a ~10‐7 rejection factor against random proton‐proton collisions, and still be able to efficiently select interesting events. After a first processing level based on FPGAs and ASICS, the final event selection is based on custom software running on two CPU farms, containing around two thousand multi‐core machines. This is known as the high‐level trigger(HLT). With more than 100 contributors and around 250 different packages, a thorough validation of the HLT software is essential. This paper describes the existing infrastructure used for validating the HLT software, as well as future plans.