The Fama-French three-factor model (Fama & French, 1993) has been subject to extensive testing on samples of US and European nonfinancial firms over several time windows. The most accepted evidence is that size premium (SMB) and value premium (HML) other than the market risk premium help explain cross-section and time-series changes in stock returns. However, scholars have always paid little attention to the financial industry because of the intrinsic differences between financial and nonfinancial firms. The few studies that tested the model on financial firms found mixed evidence on the role of size and book-to-market ratio (B/M) in explaining stock returns. This paper tries to bridge the gap by testing the model on a sample of European financial firms. We find that size and B/M factors seem to be sources of undiversifiable risks and should therefore be included as risk premiums for estimating expected returns of financial firms. Small and high-B/M firms show higher returns that are not explained by market risk and the inclusion of SMB and HML helps improve the regression models’ goodness-of-fit.