Background & aims: Postprandial lipemia has been associated with inflammation, oxidative stress and vascular dysfunction. This metabolic disturbance represents a complex process only partly understood. The purpose of this study was to identify variations in plasma proteome after a high-fat challenge in healthy middle-aged men. Methods: Two-dimensional electrophoresis was used to compare plasma from seven subjects, drawn before and 4 h after a high-fat challenge. Results: Among the 231 spots detected and analyzed, 22 were present at different levels in postprandial hyperlipemic plasma compared to preprandial plasma. For 10 of them, corresponding proteins were identified by mass spectrometry. Some of them are related to the hemostatic system (tetranectin and fibrinogen) or the complement system (complement component 3 and 4 and ficollin-3) and have been previously associated to atherothrombosis. Conclusion: These results provide new perspectives and broaden our understanding of the biological processes of postprandial metabolic stress, as well as its links with the development of atherosclerosis. (C) 2012 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.