To explain why member libraries were failing to fill interlibrary loan requests, this study surveyed 26 public, school, community college, university, and special libraries throughout the Cooperative Information Network (CIN). The study was designed to discover: which libraries were chosen for loans, how soon patrons wanted loan information, how long it took to fulfill patron's request, the effectiveness of the source choice, and material (by subject area) that was not available. It was determined that CIN was fulfilling its major objective of providing better library service to all its constituents, but there was room for improvement in the number of non-filled requests with no reply (32% in this study). Study results are presented in 14 statistical tables. (DS)