Interest in DNA repair in Aspergillus nidulans had mainly grown out of studies of three different biological processes, namely mitotic recombination, inducible responses to detrimental environmental changes, and genetic control of the cell cycle. Ron Morris started the investigation of the genetic control of the cell cycle by screening hundreds of cell cycle temperature sensitive Aspergillus mutants. The sequencing and innovative analysis of these genes revealed not only several components of the cell cycle machinery that are directly involved in checkpoint response, but also components required for DNA replication and DNA damage response machinery. Here, we will provide an overview about currently known aspects of the DNA damage response in A. nidulans. Emphasis is put on analyzed mutants that are available and review epistatic relationships and other interactions among them. Furthermore, a comprehensive list of A. nidulans genes involved in different processes of the DNA damage response, as identified by homology of genome sequences with well-characterized human and yeast DNA repair genes, is shown.