This manuscript reports a study of the secondary-school library. The library, it is claimed, exists first to improve the curriculum, and second, to encourage reading as a leisure-time occupation. The purposes of this investigation are: (1) to list and describe activities and devices used in outstanding secondary-school libraries; (2) to present data regarding the administration, staff, and facilities of libraries in secondary schools from studies already made as well as from facts regarding libraries in schools recommended as having outstanding library service; (3) to interpret certain problems of the secondary-school library in the light of evidence from a study of the use made of outstanding high-school libraries; and (4) to propose for further investigation problems relating to the secondary-school library. This study was made both by inquiry form and personal visit of Doctor Johnson. The returns to the inquiry form were received from 390 schools located in 46 of the States and in the District of Columbia. Of these schools, 163 were 4-year high schools, more than half of them had enrollments of 750 or fewer pupils. Fifty-five had enrollments of more than 2,000. It seems likely that these schools are representative. In the personal visitation Doctor Johnson spent usually a day in each school. He visited altogether 44 schools in 15 of the States. This study shows inadequate facilities as the main difficulty encountered by librarians. The Dewey decimal system of classification is the dominant method of cataloging. In practically all the libraries teachers are invited to submit their lists of books before purchases are made. Too frequently, however, the library is in charge of a teacher who has a full-time teaching load. She is often assisted by pupil assistants, but this is not entirely satisfactory. It was found that most of the librarians do not approve of having the library and study halls combined, but nevertheless this method did produce the best results and was favored by the pupils and by the principals. It was found that the junior high school pupils use the library for pleasure reading more than do the senior high school pupils. To the latter the library is a workshop. Some experimentations are being made with classroom libraries, departmental libraries, and the like; but there is little cooperation found between the school libraries and public libraries. Library service in the small high school has not been so successfully developed as in larger places, due to scarcity of books and untrained librarians generally. (Contains 42 tables, 9 figures, and 42 footnotes.) [Best copy available has been provided.]