This article examines the effect of gender on legislators' attitudes and bill initiation behavior in three Latin American countries—Argentina, Colombia, and Costa Rica. I argue that sex role changes in Latin America over the past 35 years have led to changes in how female legislators perceive their political roles, and consequently, changes in their attitudes and behavior. Specifically, female legislators will place higher priority than male legislators on women's issues and children/family concerns, but their attitudes in other areas, such as education, health, the economy, agriculture, and employment, will be similar. However, I expect that gender dynamics in the legislative arena lead to marginalization of women such that gender differences will emerge for bill initiation behavior where they did not appear for attitudes. I test this using a survey of legislators' issue preferences and archival data on the bills that legislators sponsor and find statistical support for the hypotheses.