This paper presents three indicators of vertical and horizontal occupational segregation to describe trends in women’s participation in eight disciplines and five academic levels in 1973, 1987, and 2001. The most common index, the index of occupational dissimilarity (D), the new Charles and Grusky [1995, American Journal of Sociology 100, 931–971] Index of Association (A), and the representation ratio are computed and compared. Although there are limits associated with D, the sparseness of women’s participation in academic science and engineering in 1973 posed computational problems with A. Key findings are: (1) levels of vertical segregation were higher than horizontal segregation and (2) levels of segregation (horizontal and vertical) have not declined substantially over the past 28 years. The same procedures are applied to data available for six of the nine “first round” ADVANCE institutions in an exploratory analysis for data from 2001 to 2003/04. Policy implications of these findings are discussed.