Updated project metadata. Odorant-Binding Proteins (OBP) are players of perireceptor events in olfaction. A molecular mechanism explaining their specificity for odors and pheromones has still to be proposed. A new track comes from the analysis of pig olfactory secretome, which is mainly composed of OBP isoforms, generated from 3 gene products by PTM, phosphorylation and O‐β‐N‐acetylglucosaminylation (O-GlcNAcylation), which are unusual for secreted proteins. These diverse isoforms could display different binding properties towards ligands. Before testing such a function, both post-translational modifications, although assessed by specific antibodies, have to be identified by mass spectrometry. We report here for the first time, the identification of phosphorylation and O-GlcNAcylation on peptides coming from trypsin digestion of OBP by ESI-HCD-MS/MS. PEAKS software analysis of raw MS data allowed selecting spectra that were analyzed manually to identify PTM. Four peptides corresponding to two different portions of OBP sequence were modified either by a phosphate group or by a hexNAc moiety. Due to the high energy used in HCD, the data did not allow precise localization of the modified sites. We suggest that these two PTM, by generating multiple isoforms, should extend the binding repertoire of secreted OBPs