Human umbilical vein endothelial cells are the most widely used in vitro model for endothelial cells. Their secreted proteins, however, have not been comprehensively analysed so far. In this study, we accomplished to map the secretome of human umbilical vein endothelial cells by combining free-flow electrophoresis with nanoflow LC-MS/MS. This comprehensive analysis provides a basis for future comparative studies of protein secretion by endothelial cells in response to cardiovascular risk factors and is available on our website http://www.vascular-proteomics.com.