Taking into account the increasing complexity and scale of construction projects recently, interface management (IM) has been emerging as an important aspect of project management practices. It is believed that effective IM improves alignment and reduces conflicts among project stakeholders by increasing visibility on roles, responsibilities and deliverables, particularly in large projects. The recent improvements in the communications and information management technologies make it possible for the global mega-project, such as oil-sand, off-shore facilities, to employ IM as a part of their project management process. Mega-projects generally are defined to be more than $1 billion; however, projects with lower cost but high organizational and interface complexity are also good candidates for IM adoption. Although there is a high demand for IM, it has not been well-defined yet, which limits its full adoption. As part of a research program to identify and establish the definitions and best practices of IM, sponsored by the Construction Industry Institute (CII), the authors investigated the current state of IM in 37 projects. These projects, including owners and contractors working within different construction sectors, are surveyed according to their general characteristics (e.g., cost, project types, etc.) and IM adoption. Furthermore, the research team analyzed the IM adoption with respect to several interface risk and complexity factors within these projects. The expected contributions of the research will be a comprehensive study of the current state of IM in construction mega-projects, identifying the factors that may lead to implementing IM in projects, and providing the definitions and preliminary principles for establishing effective IM.