Peter Højrup graduated from Aarhus University, Department of Molecular Biology. He then went on and obtained a Lic. Scient. degree (Ph.D.) from Odense University (now University of Southern Denmark), Department of Molecular Biology, in the emerging field of protein mass spectrometry under the supervision of Prof. Peter Roepstorff. The main focus of the study was development of new methods for primary structure elucidatin by coupling classical protein chemical methods with mass spectrometry. After a couple of years as a postdoc at the University of Aarhus, he returned to Odense where he rejoined Peter Roepstorff's group. In 1991 he became associate professor at Department of Biochemistry and Molecular Biology, University of Southern Denmark, where he since 2008 has been professor MSO.