The sensitivity of LiTaO3crystals to hologram formation has been observed to vary with impurity concentration. For a writing wavelength of 488.0 nm and power density of 1.1 W/cm2the sensitivity varied from a value comparable to the most sensitive doped LiNbO3for an impure crystal to a value more than 5 orders of magnitude smaller for a purer crystal. Fatigue effects were observed upon write‐erase cycling. These effects were dependent upon writing and erasure polarization and power density and could be minimized by proper choice of optical parameters.