We have measured the magnetostriction of a TbFe2 (110) film, grown by MBE, by using a cantilever capacitive technique. The magnetic field was applied along the [1(1) over bar 1] easy direction of the film, to determine the rhombohedral distortion of the cubic lattice. The isotherms, performed between 300 and 10 K, clearly display the coercive field, which increases as the temperature decreases, in agreement with the increase of the anisotropy of the Tb ions. Unlike bulk alloy behavior, the magnetostriction does not saturate even at the maximum field of 12 T. The determined magnetoelastic constant of the film is similar to the known value for bulk single-crystalline TbFe2.