Hospital databases can be used to evaluate drug prescription quality with the help of drug utilization review (DUR). A DUR appraises the appropriateness of prescribing by means of explicit criteria established in accordance with evidence-based data, and then suggests interventions designed to modify prescriber's practice. On the one hand, the capacity of the review to show the variations, and, on the other hand, the assessment of the impact of interventions implemented to correct those variations, depend on the quality of hospital databases. This article has two objectives: to identify the required data, both to carry out a DUR and to evaluate its outcomes, and to define the essential qualities of hospital databases.