The mechanisms mediating the repair of DNA damage in human cells have been the focus of a multitude of studies since the middle of the previous century, and many of the proteins implicated in these processes have been identified as being part of large macromolecular assemblies. This review gives an overview of the current knowledge of protein structures specifically involved in the repair of DNA double strand breaks through Non-Homologous End Joining, with a focus on recent structures obtained via cryo-electron microscopy and prospects for how this rapidly evolving method will impact our understanding of DNA repair.