From its beginnings, Women's Studies has faced challenges due to use of the concept "discipline" to identify bodies of knowledge and to construct institutional boundaries in the academy. With its multiplicity of approaches, Women's Studies crosses lines between realms of knowledge that are typically identified with departments, creating difficulties for students and faculty who pursue intellectual and institutional goals that do not fit the usual rules. While creation of cross-departmental committees to oversee most undergraduate women's studies programs has served to overcome some of these problems, recent trends, toward both departmentalization of Women's Studies and development of doctoral programs, highlight the importance of reviewing the institutional as well as epistemological history through which current disciplinary and departmental borders were established. Situating Women's Studies within another history, that of interdisciplinary research and teaching, the author suggests that women's studies practitioners adopt an empirical, "both/and" stance toward the problem of disciplinarity, continuing to establish Women's Studies with disciplinary departments while also participating in whatever types of cross-disciplinary units best fit their intellectual interests and specific institutional histories and structures. Women's studies practitioners should both engage the disciplines and cross boundaries, especially in order to learn from each other. We can take satisfaction in recognizing the extent to which traditional vertical divisions in many areas of life are giving way to horizontal groupings, and identities becoming more diffuse, multiple, and flexible, thus creating new constructions more congenial to Women's Studies than the disciplinary divisions that are now deemed "traditional."