Hydrothermally synthesized hydrogen titanate (H2Ti 3O7) nanotube meshes and arrays exhibit excellent field emission characteristics. The turn-on field is as low as 1.4 V μm -1 for the mesh and 2.6 V μm-1 for the array, while the electric field corresponding to an emission current density of 10 μA cm -2 is 2 V μm-1 (mesh) and 3.8 V μm-1 (array). The H2Ti3O7 nanotube mesh has one of the lowest reported turn-on voltages and highest enhancement factors. The emission current also shows good long term stability. We attribute the efficient field emission to the presence of mid-gap states arising from the negative surface charge on the H2Ti3O7 nanotubes.