Selected tensor property coefficients of the nonlinear optical crystal LiB3O5are reported. The full set of pyroelectric, dielectric, and thermal expansion coefficients were measured as a function of temperature. The five independent piezoelectric coefficients, the full set of electromechanical coupling coefficients, along with the compliance constants, were measured at room temperature. The material was found to be quite anisotropic in most property coefficients. The piezoelectric and electromechanical coupling coefficients were reasonably low, and comparisons are made between LiB3O5and other borate crystals. The material showed strong ionic conductivity along the ⟨001⟩ direction, with a calculated activation energy for Li transport of 0.43 eV. ©1995 American Institute of Physics.