An NMR characterisation of the perovskite LaGaO3 using the isotopes Ga-69.71 and La-139 has been used to provide, via measurement of the nuclear quadrupole interaction (NQI), an independent confirmation of the orthorhombic distortion from ideal cubic. The NMR lineshape changes consequent on doping LaGaO3 with 2, 5, 7.5 and 10 mol% of both SrO and MgO to achieve (eventually) the cubic form have been observed and interpreted in terms of a distribution of local electrical field gradients due to substitution on La and Ga sites on the Sr2+ and Mg2+ ions, respectively. Crown Copyright (C) 2004 Published by Elsevier B.V. All rights reserved.