As “market referees”, regulators contribute to the delivery of essential public utilities. Their organisational culture, behaviour and governance are important factors in how regulators, and the sectors they oversee, perform. The report uses the OECD Performance Assessment Framework for Economic Regulators to assess both the internal and external governance of Peru's Energy and Mining Regulator (Osinergmin). The review discusses Osinergmin's achievements and good practices, analyses the key drivers of its performance, and proposes an integrated reform package to help the regulator prepare for the future.