Although apparently simple and efficient to use, removable appliances are no longer the appliance of choice for comprehensive orthodontic treatment in the permanent dentition. Their mechanical properties result in simple tipping of teeth, therefore multiple simultaneous tooth movements with apical control are not possible. It is for these and other reasons that removable appliances are usually only indicated for specific interventions in the mixed dentition, and as an adjunct to more complex fixed appliance treatment. Removable appliances, once popular because of their ease of use, are no longer seen as the appliance of choice. This article discusses the rationale behind this statement and indicates cases suitable for removable appliance treatment.