Solid particle erosion testing of an ultrafine-grained Grade 5 titanium alloy which was modified using high pressure torsion (HPT) technique is presented. In order to assess influence of HPT treatment on material's behavior in erosive conditions special experimental procedures were developed. The ultrafine-grained (UFG) alloy was tested alongside with a conventional coarse-grained (CG) Grade 5 titanium alloy in equal conditions. The experiments were conducted in a small-scale wind tunnel with corundum particles as an abrasive material. Both particle dimensions and particle velocities were varied in the experiments. The erosion resistance was evaluated in two different ways - mass reduction measurement method and assessment of samples' surface roughness after erosion tests. While the UFG titanium alloy demonstrated considerable improvement of static mechanical properties (ultimate tensile strength microhardness) its CG counterpart appeared to be more resistant to high speed erosion which might indicate drop of dynamic strength properties for the HPT-processed material.