Substitution of branded medicines by cheaper generic medicines has been and is subject for debate in the Netherlands. One of the tasks of the Dutch Medicines Evaluation Board (CBG) is the evaluation of generic medicines. The way the CBG approves generics, as outlined in this paper, is based on assessment of the quality of the medicine and bioequivalence testing according to strict European guidelines. Registration of generic medicines in the Netherlands will only take place when bioequivalence has been demonstrated. Once bioequivalence has been demonstrated, the CBG is convinced that the generic has the same efficacy and safety as the branded medicine. Consequently, the CBG is of the opinion that the branded medicine can be safely exchanged with the generic medicine. However, for the acceptance of generics in daily practice adequate communication to the patient by prescriber, pharmacist, health insurance company and patient organisations is essential.