Maintaining usable and sustainable digital collections necessitates maintaining high-quality metadata about those digital objects. The two aspects of digital library data quality are the quality of the data in the objects themselves, and the quality of the metadata associated with the objects. Because poor metadata quality can result in ambiguity, poor recall and inconsistent search results, the existence of robust quality assurance mechanisms is a necessary feature of a well-functioning digital library. In order for end users to benefit fully from the development of digital libraries, responsible and viable service providers need to address metadata quality issues. Based on the University of North Texas Libraries experiences, this paper discusses issues related to metadata quality management and demonstrates a number of tools, workflows and quality assurance mechanisms.