Pseudoelasticity in monocrystalline Fe3Al (23 at.% Al) was investigated by room-temperature mechanical testing along the <418> tensile and compressive axes. In tension, up to ∼10% strain is recoverable whereas only ∼5% strain is recoverable in compression. Straight, parallel, surface step lines were seen to appear/disappear as the specimens were pseudoelastically loaded/unloaded. In contrast, in the plastic region (ε >10%), wavy slip lines appeared on the specimen surfaces which did not disappear upon unloading. In-situ neutron diffraction was performed during compressive straining and the intensities of several diffraction peaks increase/decrease reversibly during loading/unloading. These changes are consistent with a deformation twin which produces large crystal rotations. They could also be indicative of a phase transformation. Unfortunately, we were able to sample only a limited range of 2θ in the present investigation and, within this range, none of the new peaks that appeared during the pseudoelastic deformation were disallowed peaks for the D03 crystal structure. Therefore we are unable at this time to distinguish between the two possible mechanisms, twinning and phase transformation.