The Harmonization of Seismic Hazard Maps in the Western Balkan Countries Project (BSHAP) was funded for 7 years by NATO-Science for Peace Program to support the preparation of new seismic hazard maps of the Western Balkan Region using modern scientific tools. One of the most important outputs of the BSHAP is an updated and unified BSHAP earthquake catalogue that is compiled directly from the datasets of earthquake data providers of the region. The BSHAP earthquake catalogue described here covers the geographic area limited by 38.0 degrees-47.5 degrees N, 12.5 degrees-24.5 degrees E and includes 26,118 earthquakes that occurred in the region between 510 BC and 2012. Details of data compilation efforts including the removal of duplicate events, unification of the magnitude scales, declustering of the catalogue and completeness analysis are presented in this manuscript. New magnitude conversion equations for various local magnitude scales of the data providers are developed with the aim of having homogeneous moment magnitude estimates. Completeness time intervals for the catalogue data are provided as inputs to the seismic source models used to obtain updated seismic hazard of Western Balkan Region. The unified and updated BSHAP catalogue is found to be compatible with the current well-established European and world-wide catalogues and represents a sound basis for analysis of the seismicity of this region.