This chapter describes the implications for managing metadata, a higher-level abstraction of data that exists within repositories, applications, systems and organizations. Metadata is a key factor for the successful implementation of complex decision environments. Managing metadata offers significant benefits and poses several challenges, due to the complex nature of metadata. The complexity is demonstrated by reviewing different functions that metadata serves in decision environments. To fully reap the benefits of metadata, it is necessary to manage metadata in an integrated manner. Crucial gaps for integrating metadata are identified by comparing the requirements for managing metadata with the capabilities offered by commercial software products designed for managing it. The chapter then proposes a conceptual architecture for the design of an integrated metadata repository that attempts to redress these gaps. The chapter concludes with a review of emerging research directions that explore the contribution of metadata in decision environments.