Gender research in mathematics education has experienced methodological and theoretical shifts over the past 45 years. Although achievement studies have used assessment tools to explore and subsequently challenge the assumption of male superiority on mathematics assessments, research on participation has unpacked these studies' sex-based achievement comparisons by exploring the masculinization of mathematics through qualitative methods. This article offers a review of gender research in mathematics education with analysis of its findings as well as conceptual and empirical contributions. Current understanding of mathematics as a gendered space, however, can be further broadened through intersectional analyses of gender and its interplay with other identities (e.g., race or ethnicity, class). Implications for future gender research, particularly the adoption of intersectionality theory, are raised to inform more nuanced analyses.