Summary: A protein-protein docking decoy set is built for the DOCKGROUND unbound benchmark set. The GRAMM-X docking scan was used to generate 100 non-native and at least one near-native match per complex for 61 complexes. The set is a publicly available resource for the development of scoring functions and knowledge-based potentials for protein docking methodologies. Availability: The decoys are freely available for download at http://dockground.bioinformatics.ku.edu/UNBOUND/decoy/decoy.php Contact: vakser@ku.edu 10.1093/bioinformatics/btn497