We conduct a comprehensive synthesis of the research on how female representation in the upper echelons (i.e., top management teams and CEO positions) might affect firm performance. To help resolve longstanding theoretical, empirical, and substantive debates, we present an integrative conceptual framework based on the overarching concepts of unique resource portfolios, team decision-processes, and role incongruence perceptions. We test predictions from this framework using meta-analytic techniques on a sample of 146 primary studies conducted in 33 different countries. We find that female representation in the upper echelons in general is positively and weakly related to forms of long-term financial performance, but negatively and weakly related to short-term stock market returns. We observe that reduced strategic risk-taking is a mediating mechanism that explains why financial performance is improved. We also show that financial performance improvements are accentuated in environmental and organizational contexts that provide greater decision latitude to executives. Finally, we discuss and provide preliminary tests for extending these effects to other stakeholders (CSP) and different time intervals for performance.