The growing literature on gender inequality in academia attests to the challenge that awaits female researchers during their academic careers. However, research has not yet conclusively resolved whether these biases persist during the peer review process of research grant funding and whether they impact respective funding decisions. Whereas many have argued for the existence of gender inequality in grant peer reviews and outcomes, others have demonstrated that gender equality is upheld during these processes. In the present paper, we illustrate how these opinions have come to such opposing conclusions and consider methodological and contextual factors that render these findings inconclusive. More specifically, we argue that a more comprehensive approach is needed to further the debate, encompassing individual and systemic biases as well as more global social barriers. We also argue that examining gender biases during the peer review process of research grant funding poses critical methodological challenges that deserve special attention. We conclude by providing directions for possible future research and more general considerations that may improve grant funding opportunities and career paths for female researchers.