Cross-talk between distinct protein post-translational modifications is critical for an effective DNA damage response. Arginine methylation plays an important role in maintaining genome stability, however how this modification integrates with other enzymatic activities is largely unknown. Here, we identify the deubiquitylating enzyme USP11 as a previously uncharacterised PRMT1 substrate, and that methylation of USP11 promotes DNA end-resection and the repair of DNA double strand breaks by homologous recombination (HR). In addition, we show that PRMT1 is a ubiquitylated protein that it is targeted for deubiquitylation by USP11, and that USP11 regulates the ability of PRMT1 to bind to and methylate MRE11. Interestingly, USP11 methylation by PRMT1 is not required for other USP11 activities during HR, such as PALB2 deubiquitylation. Taken together, our findings reveal a specific role for USP11 during the early stages of DSB repair, which is mediated through its ability to regulate the activity of the PRMT1-MRE11 pathway.