Under well-controlled synthesis conditions, MgO was produced in powdered form by means of conventional metal combustion technique. Resulting so-called smoke nanoparticles consist of single crystallites with exceptionally regular cubic shape. We demonstrate that their size and distribution are strongly dependent on the synthesis parameters. The effect of the oxygen partial pressure on the synthesis has been systematically studied by transmission electron spectroscopy. It was shown that an increase in oxygen partial pressure leads to a decrease in MgO particle size. This is rationalized on the basis of the classical theory of nucleation and growth. More general applications of this approach are discussed. (C) 2011 Elsevier B.V. All rights reserved.