Inadequate antibiotic prescribing has been observed in many settings both in hospitals as well as in primary care. Most often there is uncertainty about the indication for antibiotic treatment itself, prescribers are reluctant to deescalate, and therapy duration is too long which results most often in overprescribing. The burden of overprescribing is difficult to estimate, but many studies in the hospital setting report a rate of approximately 30 % of inadequate prescribing – with wide variation. Over- but also underprescribing of antimicrobial agents is a serious patient safety issue that needs to be addressed in specific programmes at different levels of the healthcare system. Interventional studies have shown that programmes implementing or intensifying audit and feedback with clinical reevaluation by experts can be very efficient to reduce inadequate prescribing.