The purpose of this review is to discuss interesting recent developments concerning the use of halogenated agents. Now we are in a new stage of halogen use; we have become alerted to the secondary effects which although not life-threatening are potentially deleterious.The recent literature highlighted some unexpected effects with the use of new halogens such as emergence agitation associated with rapid elimination of new anesthetics, or epileptogenic effect of sevoflurane. In addition, recent advances in monitoring of depth of anesthesia may contribute to a more-precise dosing of halogens and concomitant decrease of the deleterious side effects.Based on this new approach, the therapeutic range of the new halogenated agents may be revisited and possibly narrowed.