Success in pursuing cross-disciplinary objectives in collaborative research and practice often requires the meaningful integration of different contributing perspectives, where this entails that the perspectives influence the final outcome without getting lost in the process. To effect this kind of integration, there must be communication among collaborators. How else will collaborators with non-overlapping expertise collectively weave together their contributions into an integrated final product? Both of these require some level of cooperation among collaborators, where this typically involves both social interaction and epistemic exchange. This chapter expands on these observations and provides a more detailed analysis of communication, integration, and the relationship between them. This chapter asks, in the context of cross-disciplinary research and practice, the following three questions: (a) What are communication and integration? (b) What special challenges do communication and integration pose? and (c) Generally, how can these challenges be overcome? The chapter concludes by discussing relations among communication and integration that contribute to the problematic nexus of challenges that surround these central concepts.