The interest in the preparation of nanoscale oxide semiconductors of the In–Ga–Zn–O system is due to the rapid development of printed electronics and solar cells. There are numerous methods for the synthesis of oxide nanomaterials (coprecipitation, sol-gel, self-combustion, etc), including a relatively novel reverse micelle synthesis. In the present study, In2O3, Ga2O3, ZnO oxides are prepared using self-combustion, and reverse micelle synthesis. The phase composition and morphology of the obtained oxides are described. The average size of their particles is determined from the XRD data, scanning electron microscopy, specific surface area, and dynamic light scattering of the suspensions of prepared powders. It is shown that the finest oxide powders are obtained by the reverse micelle synthesis.