Regulators are proactive referees of the sectors they regulate, contributing to the delivery of essential public utilities for citizens. To fulfill this function, they need to be constantly alert, checking sectoral trends as well as assessing the impact of their decisions. However, while measuring regulators’ performance is essential, it is also challenging, from defininig what should be measured to attributing impacts to regulators' decisions. To address these challenges, the OECD has developed an innovative framework that looks at the institutions, processes and practices that help regulators assess their performance. The framework has been applied to Latvia's Public Utilities Commission, which is responsible for regulating energy, communications, water and waste. The review offers unique insights into the work of a multi-sector regulator, identifying the organisational features that allow lessons and experiences to be shared across sectors and contribute to good performance. It highlights the importance of clarifying the role and functions of the regulator and its relationship with other public institutions, setting long-term strategic objectives for the regulator's activities, and having the right regulatory tools with appropriate incentives for the efficient and effective provision of public utility services.