Transparent-conducting thin films of zinc oxide were prepared by vacuum evaporation and spray-pyrolysis techniques. A simple set-up for production of atomic-hydrogen plasma was designed and made. ZnO samples were hydrogenated at different substrate temperatures and for different hydrogenation times. Hydrogenation at a substrate temperature of 250 degreesC for 45 min considerably increased the electrical conductivity of ZnO films (approx. by 340%). Hall measurements showed that the hydrogenation process did not change carrier concentration in the films greatly. Thus the increase in the conductivity can be essentially attributed to a considerable increase in carrier drift mobility. This in turn, is attributed to deactivation of dangling bonds ' associated with the structural defects in ZnO films by hydrogen ions. It was also found that the hydrogenation process did not noticeably affect optical transparencies and microstructure of the films.