By performing Z-scan method with a femtosecond laser (800 nm, 50 fs, 1 kHz), we investigated the third-order optical nonlinearities of a cuprous oxide (Cu2O) film. Single-phase Cu2O film deposited on a quartz substrate was obtained using the pulsed laser deposition technique. The structure properties, surface morphology and optical transmission spectrum were characterized by X-ray diffraction, scanning electron microscopy and double beam spectrophotometer, respectively. The Z-scan results show that the Cu2O film exhibits large nonlinear refractive index. n(2)=3 x 10(-3) cm(2)/GW, while the two-photon absorption coefficient, alpha(2)=40 cm/GW, is relatively small. It implies that the Cu2O film is a promising candidate for nonlinear photonic devices. (C) 2011 Elsevier B.V. All rights reserved.