This report investigates the gender gap in the funding of innovative start-ups across OECD and BRICS countries using a detailed micro-dataset on start-ups and their founders. Results from empirical analysis show that start-ups with at least one woman in the team of founders are less likely to receive funding by 5-10%. When such start-ups do receive funding, they receive an amount lower by a third compared to start-ups created by male founders. Accounting for founders’ characteristics (their educational background and past professional experience) reduces the gap in likelihood to receive funding, but not the gap in funding amounts. A key conclusion is that addressing the gender gap will require a holistic approach, including through – but not restricted to – the education system. The paper concludes by a discussion of potential mechanisms that could explain the observed gap, presents policy options, and proposes an agenda for future research.