The size and nature of copper powders deposited in conditions close to those found in production units are investigated with a scanning electron microscope. It is shown that an increase in the current density or the concentration of sulphuric acid decreases the size of the particles and makes their dendritic structure more pronounced. In contrast, an increase of copper ion concentration or agitation increases the size of the particles and obscures their dendritic character. It is shown that the changes in the particle size and type are primarily dependent on cathode potential. A change from −100mV to —900mV versus SCE causes a decrease in the powder size from 80–100μm to 5–10μm and a successive appearance of the following types of particles: (a) round particles or dendrites with round tips, due to electrocrystallization in one plane (a compact deposition); (b) a transient structure, apparently a change to polycrystal growth on the pyramidal tips; (c) particles with pyramidal tips and (d) dimeric and trimeric dendrites.