Abstract: The present invention relates to the identification of peptides, and the corresponding proteins, that can be used in methods for the detection of autologous blood doping. More specifically, the invention relates to methods comprising tryptic digestion of samples of isolated red blood cell (RBC), specifically isolated RBC cytosol, followed by peptide mapping using liquid chromatography tandem-mass spectroscopy (LC-MS/MS). The methods according to the invention which enable detection of increased levels of certain peptides in samples from subjects that have been subjected to autologous blood doping, compared to samples from non-doped control subjects.