Rickettsia conorii is the etiologic agent of Mediterranean spotted fever, a re-emerging disease with significant mortality. This obligate, gram-negative intracellular pathogen is transmitted via tick bites, resulting in disseminated vascular endothelial cell infection with vascular leakage. In the infected human, Rickettsia conorii infects endothelial cells, stimulating expression of cytokines and pro-coagulant factors. However, the integrated proteomic response of human endothelial cells to R. conorii infection is not known. In this study, we performed quantitative proteomic profiling of R conorii –infected primary HUVECs vs those stimulated with LPS alone.