Résumé : In a context where MIVs face several bottlenecks regarding their future role in the microfinance industry, this paper suggests a brand new way of reviewing their commitment to double bottom line returns. We suggest using the MACBETH (Measuring Attractiveness by a Categorical Based Evaluation TecHnique) approach as an investment screening method which, combined to existing social performance tools such as the Social Performance Indicators, can ensure that investment decisions are taken in accordance with socially responsible investors’ values. This approach could contribute to the emergence of the transparency MIVs need in ensuring the whole sector that their commitment to double bottom line returns is real.