Microcephalin (MCPH1) is one of the causative genes for the autosomal recessive disorder, primary microcephaly, characterized by dramatic reduction in brain size and mental retardation. MCPH1 also functions in the DNA damage response, participating in cell cycle checkpoint control. However, how MCPH1 is regulated in the DNA damage response still remains unknown. Here we report that MCPH1’s ability to localize to the sites of DNA double-strand breaks (DSBs) depends on its C-terminal tandem BRCT domains. While MCPH1 foci formation depends on H2AX phosphorylation following DNA damage, it can occur independently of MDC1. We also show that MCPH1 binds to a phospho-H2AX peptide in vitro, with an affinity similar to that of MDC1 and overexpression of wildtype, but not C-BRCT mutants of MCPH1, can interfere with the foci formation of MDC1 and 53BP1. Collectively, our data suggests MCPH1 is recruited to DSBs via its interaction with gH2AX, which is mediated by MCPH1’s C terminal BRCT domains. These observations support that MCPH1 acts early in DNA damage responsive pathways.