Defining centralized processing as ordering, cataloging, classification, and mechanical preparation of library materials, this study was conducted (1) to determine the feasibility of centralized processing for illinois public libraries and library systems and (2) to make recommendations for planning state centralized activity. General survey techniques used to collect data included a literature search, contact with individuals involved in similar activity, and visits to processing centers, system headquarters, and libraries in illinois and other states. It was found that centralized processing in illinois is fragmented and underdeveloped, and state-wide application has not been considered. A profile of selected illinois libraries shows that most do not use centralized processing services, but library technical procedures are basically standard and there is a positive attitude toward such a future service. It is concluded that centralized processing is feasible and should be developed as a coordinated, state-wide program. Recommendations include (1) development of the book processing center at oak park as the state's single processing center, (2) use of an electronic data processing and communications system, (3) a quasi-independent status for the center if possible, and (4) an advisory committee. The questionnaires, survey criteria, and a bibliography of 49 items are appended. (Jb).