Using an index of dissimilarity based on data from the Annual Survey of Industries for 1989/90 and 2000/01, the authors find that sex segregation across India's so-called factory sector decreased over this period. Most of the apparent improvement, however, was due to changes in the industrial structure of employment, not desegregation per se. The index is also sensitive to the number of industries in the underlying classifications. At the national and state levels, formal job opportunities for women are effectively very limited: they are highly concentrated in a small number of traditional “women's” manufacturing industries, such as food, tobacco, apparel, weaving and spinning.