Ever since the identification of the first protein-arginine kinase, McsB, in B. subtilis arginine phosphorylation gained more attention. However, the analysis of phosphorylations especially phosphormaidates comes along with several challenges. The sub-stoichiometric nature of protein phosphorylation requires proper enrichment strategies prior to LC-MS/MS analysis and the acid instability of phosphoramidates was long though to impede those enrichments. Further good spectral quality is required which can be reduced by the presence of neutral losses of phosphoric acid upon higher energy collision induced dissociation. Adaptation of common enrichment strategies to less acidic conditions and the use of electron-transfer dissociation allowed the identification of more than 200 pArg sites in B. subtilis and S. aureus so far. Here we show that pArg is stable enough for commonly used Fe3+-IMAC enrichment followed by LC-MS/MS and that HCD is still the gold standard for phosphoproteomics. By profiling a serine/ threonine kinase (Stk1) and phosphatase (Stp1) mutant from a methicillin-resistant S. aureus mutant library, we identified 1062 pArg sites and thus the most comprehensive arginine phosphoproteome to date. Using synthetic phosphoarginine peptides we validated the presence and localization of arginine phosphorylation in S. aureus and lastly, we could show that Stp1 is influencing the arginine phosphoproteom without being a protein-arginine phosphatase.