Analysis of data recorded in 626 questionnaires on systems used to automate medical libraries by type of library showed that academic and industrial libraries automated all serial and book functions to a greater degree that the other types of medical libraries (hospital, governmental, institutional and medical centre). Almost 75% of the academic libraries had automated some or all serial functions; 80% had automated some or all book functions. Half of the hospital, institutional and medical centre libraries (50–51%) performed all serial functions manually; 29–40% performed all book functions manually. No software was used consistently by all types of libraries to process serials or books. Mainframe or minicomputers were used more by academic libraries to process serials and books than personal computers.