Cities around the world are gearing up to play a major role in climate change mitigation. However, concrete results – significant emissions reductions, expected from cities committed to mitigating climate change, are currently conspicuously absent. While there are several good practice guides available for large/mega cities there are little available for small and medium-sized ones (SMCs). In this paper the main research questions are, “When exploring local climate mitigation action among multiple small- and medium-sized cities, what actions are perceived as good practices?”, and “Are there any demonstrable effects linking them to achieving climate mitigation targets, and is this monitored?” A multiple case study research approach, using quali-quantitative mixed methods with multiple types of data sources, was used to analyze thirteen SMCs in the Netherlands. Results revealed twenty six good practices, with the majority exhibiting the characteristics of governing by enabling. However, no evidence was found that these good practices had been embedded in indicators or protocols, nor that they led to actual GHG emission reduction. In addition, action plans were found to be incomplete, in particular regarding implementation, and municipalities were found to work in isolation, with little inter-municipal collaboration. Moreover, whereas a monitor of local climate mitigation performance exists – using output and outcome indicators - it was found to be hardly known nor used among local policy makers. The results reveal a need to learn from good practices, to develop indicators that mirror these practices, and integrate them into local climate mitigation performance measurement tools. Currently, this is not the case, making it difficult to monitor local climate mitigation performance and progress vis-à-vis commitments made regarding the Paris Agreement.@en