A p-type transparent oxide semiconductor, CuGaO 2 , was grown epitaxially on (111) single-crystalline yttria-stabilized zirconia (YSZ) substrates by pulsed laser deposition (PLD). Single-phase epitaxial films were obtained in narrow conditions: i.e. 725≤T s ≤780 °C at PO 2 =6 Pa, and 3 Pa≤PO 2 ≤6 Pa at T s =750 °C. The electrical conductivity of the as-deposited films was controlled from 3.3×10 −5 S∙cm −1 to 1.7×10 −2 S∙cm −1 by increasing the oxygen partial pressure from 3 to 6.5 Pa. The hole concentration and Hall mobility of the most conductive film were 5×10 17 cm −3 and 0.2 cm 2 ∙V −1 ∙s −1 , respectively. Estimated from the conductivity, the hole concentration was controlled from ∼10 14 cm −3 to ∼10 17 cm −3 by the oxygen partial pressure. Post-annealing at 1215 °C smoothed the films surface to 0.56 nm in the root-mean-squares roughness and increased the Hall mobility to 0.8 cm 2 V −1 ∙s −1 , which is the largest value among CuGaO 2 films reported to date.