The morphology of the NiO-Al2O3 catalyst, prepared by coprecipitation, impregnation, and mechanical powder mixing with ca. 5, 10, and 20 wt% nickel treated at 400°, 700°, and 1100°C, was studied. Scanning electron microscopy is a useful technique for determining the manner of catalyst preparation for particle size estimation of catalyst components, whereas their mutual interactions become visible in the obtained images.