Few studies have compared the educational experiences and outcomes of students attending historically black colleges and universities (HBCU) to those of students attending traditionally white institutions. This study consists of three analyses that contain some justification for the continued existence of HBCUs, threatened by court decisions that question their role in equal educational systems. The study first reviews findings from a previously published study of undergraduates (H. Wenglinsky, 1996) that used a nationally representative database (the National Postsecondary Student Aid Study) to conclude that black students often choose HBCUs because costs are perceived to be, and are indeed, lower. This study also found that students at HBCUs were more likely to aspire to postbaccalaureate degrees. The second analysis used data from the American Association of Universities/Association of Graduate Schools to compare retention rates of black graduate students who had attended HBCUs or traditionally white schools. Students from HBCUs were more likely to persist in graduate studies. The final analysis compared graduate fields of study for students from the two types of schools using the 1993 database of the Graduate Record Examinations. Graduates of HBCUs were more likely to plan on entering a program in the sciences, engineering, or business than were black students from traditionally white schools. These findings suggest that HBCUs prepare black students for the sciences and engineering, professions in which they are traditionally underrepresented. Their low cost encourages many students to attend college who may not have attended any college otherwise. Both of these benefits support the continuation of HBCUs. An appendix discusses study methodology. (Contains 1 table, 7 figures, and 27 references.) (SLD)