Objective To propose a digital watermarking algorithm in contourlet domain based on computer generated holography. Methods Firstly, a binary watermarks was converted to a holographic watermark using the computer generated holography by the conjugate-symmetric extension. Secondly, the original image was subjected to two-dimensional contourlet transform, and the intermediate frequency was transformed into eight directional subband coefficients. Finally, the holographic watermark was embedded into one directional subband coefficients. Results Experimental results demonstrated that the proposed method could well resist attacks such as low-pass filtering, noise, cropping and JPEG lossy compression. And the algorithm could also survive print-scan attack. The original image was not needed during watermark extraction. The proposed algorithm was blind. Conclusion The watermarking algorithm proposed could be widely used in copyright protection of digital images.