The introduction of a system of computerized physician order entry (CPOE) decreases medication error rates by formalizing the drafting of the orders and providing alarms which announce potential side effects, drug interactions and overly high doses. The quality of the CPOE does not insure its success. Its deployment must be preceded by an assessment and update of the available computer resources, by training of the users and setting up a help-desk attainable 24 hours a day. The project must be lead by senior medical and nursing staff. A joint effort is the key to ensure the success of CPOE and facilitate its acceptability. CPOE provides opportunities for improving: patient safety, training of professionals, quality and efficiency of care. CPOE systems are an ideal basis to set up clinical protocols and clinical pathways.