That social capital matters is an established fact in the social sciences. Less clear, however, is how different forms of social capital affect gender disadvantages in career advancement. Focusing on a project-based type of labor market, namely the U.S. film industry, this study argues that women suffer a “closure penalty” and face severe career disadvantages when collaborating in cohesive teams. At the same time, gender disadvantages are reduced for women who build social capital in open networks with higher degrees of diversity and information flow. Using large-scale longitudinal data on career profiles of about one million performances by 97,657 film actors in 369,099 film productions between the years 1929 and 2010, I analyze career survival models and interaction effects between gender and different measures of social capital and information openness. Findings reveal that female actors have a higher risk of career failure than do their male colleagues when affiliated in cohesive networks, but women have better survival chances when embedded in open, diverse structures. This study contributes to the understanding of how and what type of social capital can be either a beneficial resource for otherwise disadvantaged groups or a constraining mechanism that intensifies gender differences in career advancement.