Undoped zinc oxide (ZnO) films have been prepared on sapphire substrates in a molecular beam epitaxy technique, and the films were annealed in air ambient along with a GaAs wafer. Arsenic in the GaAs wafer will evaporate, and enter into the ZnO films. In this facile way, arsenic-doped p-ZnO has been obtained. Hall measurements reveal that the hole concentration and Hall mobility of the ZnO:As films obtained in this way can reach 3.7×10 cm and 2.8 cm V S, respectively. X-ray photoelectron spectroscopy confirms the incorporation of arsenic into the ZnO films. The activation energy of the acceptors derived from temperature-dependent Hall measurement is about 164 meV.