In recent years major efforts have been made in developing digital library technologies for information seeking. This is an evolving area with many challenges for both practitioners and researchers. In particular, at the current stage in digital library development, users may still be unable to find relevant resources to solve their information problems without the help of human intermediaries. Intermediaries have traditionally served an important role in assisting library system users. Following on this tradition, information services have begun to offer human-mediated reference to assist remote users. Despite this trend, there remains an inadequate understanding of the effectiveness of these systems. This paper reports on an exploratory case study of intermediation in a hospital digital library information service. The study was focused on intermediation where user-intermediary communications were conducted through an asynchronous text-based digital medium. The goal of the research was in describing and gaining a further understanding of the processes of intermediation. The overall approach was naturalistic with grounded theory providing a framework for data analysis. The contributions of the study are evidenced in a descriptive framework of nine categories of factors perceived as affecting digital intermediation. The paper concludes with directions for future research.