Medication prescribing is a critical feature in the electronic health record (EHR). Computerized Clinical Decision Support (CCDS) for medication prescribing has the potential to improve quality of care, patient safety and reduce cost. However, its development, implementation, and maintenance in the clinical environment, are major challenges. We describe the basics of the CCDS in medication prescribing, the acquired experience of the last years at the Lausanne University Hospital (CHUV), and we expose the perspectives and future challenges in this domain.