Parametric line profile analysis has been used to separate size and Strain contributions to the peak broadening of in situ X-ray diffractograms recorded during isothermal annealing of nanocrystalline SnO2 materials. Of five kinetic models for isothermal crystallite growth, the simplified generalised parabolic model was found to be the closest to transmission electron microscopy (TEM) crystallite sizes resulting in expected (exponential) relaxation of strain. Crystallite growth and strain evolution of pure and Pd-doped SnO2 has been compared and discussed regarding possible growth mechanisms. It was shown that lattice strain, despite being very low, leads to overestimation of the activation energy for crystallite growth, if not considered in integral breadth analysis. (C) 2013 Elsevier B.V. All rights reserved.