The <<Standards, Options : Recommendations>> (SOR) project has been undertaken by the French National Federation of Cancer Centers (FNCLCC) is now part of the French National Cancer Institute. The project involves the development and updating of evidence-based Clinical Practice Guidelines (CPG) in oncology. In order to answer questions related to venous thromboembolic events (VTE) treatment and to central venous catheter thrombosis (CVCT) management in cancer patients, the SOR elaborated national guidelines, here presented in a short report. It results of a collaborative work with members from three learned societies ("société nationale française de médicine interne": SNFMI, "société française de médicine vasculaire": SFMV and "société française d'anesthésie-réanimation": SFAR).