Decision-making regarding the appropriate implementation of single item versus batch treatment requires close communication between archivists and conservators. Any time that a particular treatment approach becomes something of a standard procedure, there is a danger that the treatment system will begin to take on a life of its own. Treatments can be applied inappropriately or unnecessarily if the records are not reviewed carefully prior to treatment and individual decisions are not made. Careful examination, evaluation, and testing will always form the basis for sound archival conservation, whether the work is carried out on a batch or on a single item basis. Archival preservation activities may be clustered into several programmatic areas: provision of a stable storage environment; copying, duplicating, and reformatting; controlling access and use; disaster preparedness; and conservation treatment. This chapter concentrates on holdings maintenance and conservation treatment.