The premise that additional cooperation between the librarian and classroom teacher promoted acquisition of library skills, was investigated. The mutually exclusive subhypotheses were also tested. Twenty senior high school students in two small Mono County, California high schools served as the target population for the study. The experimental group was taught some units of library instruction by a classroom teacher-librarian teaching team. The control group received their library instruction from their regular teacher. The course outline used during instruction was identical for both groups. Pretest and posttest scores on a test of library skills were compared statistically using the mean, standard deviation, and t-tests. The students taught cooperatively by the classroom teacher and the librarian made significantly higher scores; however, both groups made significant increases in their acquisition of library skills. Null hypotheses were accepted for each of the three subhypotheses. Another research study involving larger groups of students, teachers, and librarians using the research design of this project to validate or invalidate the findings was recommended. Appendices include the library skills test used in the study, student responses to selected questions, library instruction samples, sources cited, and references. (Author/JPF)