This study examines management of microforms at libraries and institutions maintaining an active interest in their own microform collections, defined for the purpose of this study as those not only holding, but still acquiring microforms. Survey results presented here, which identify factors that contribute to retention and discard decisions -including holdings of the same content in different formats -are considered in the context of decision theory. Findings could inform current and future decisions relating to the microforms discussed here as well as to holdings in formats dependent on other technologies that will eventually change.