This paper has two aims: 1) to describe the tele-expertise system implemented in the Montpellier University Hospital (France) in order to optimize antimicrobial use 2) to analyze the prescribers' adherence to this system. For the second purpose, an observational prospective study was conducted for 12 months. Data were collected from counselling advices, which were notified in the electronic medical records. 1386 tele-expertise actions were performed. Among them, 87% were made without clinical evaluation at the bedside. The prescribers' adherence rate to a diagnosis was 79%. For the therapeutic requests, 87% of answers were fully followed. The results outline how the tele-expertise system enables both infectious disease specialists and prescribers to make better decisions in particular cases.