The purpose of this study was to identify the barriers that deter students from completing a vocational program in Oklahoma high schools. The 2,173 program leavers and 1,000 school leavers who were in vocational education as eleventh graders during the 1981-82 school year were chosen as a representative sample and were surveyed to ascertain the one most important reason they were no longer in the vocational program. Survey instruments were mailed only to the students whose home addresses were known resulting in returns from 53 percent of the 505 surveyed students identified as program leavers and 29 percent of the 363 surveyed school leavers. The barriers to program completion most often cited by program leavers were personal reasons, especially (for females) "getting married" or (for males) "got a job." Other reasons for noncompletion included "didn't like the teacher,""class didn't train for jobs I am interested in," and "didn't like school." Since the administrative process of scheduling students into classes they want and need is the biggest barrier to completion of a vocational program, it was recommended that school administrators test innovative ways to schedule classes. One way would be to set a three- or four-year plan of study for entering high school students. Efforts to allow students to enroll in their first choice of courses and to receive challenging instruction also should be increased. In addition, the study recommended that schools look into the educational effects of high school seniors taking only enough courses to graduate. The study noted that the student records on program leavers and school leavers were often incorrect. An executive summary and 23 statistical tables are included. (KC)