This paper builds on the outputs of the book “Ecosystem Services – Global Issues, Local Practices” (Jacobs et al. 2013) with contributions from more than 80 authors from the BEES (Belgium Ecosystem Services) community of practice. In this context, we recently performed a (non-exhaustive) review of how the ecosystem service (ES) concept could be useful to Belgian and international policy actors. As the ultimate goal of ES valuation is to improve the well being of every individual now and in the future (MEA, 2005), this paper intends to elaborate on the concept of ES valuation and how it could (not?) reach the intended goal. A clear tension appears between policy actors’ desire to acquire tools for monetary valuation and the risks posed by monetary valuation (e.g. commodification of nature, neglect of other values…). On the one hand, there is the need for ‘proof of concept’, and the availability of economic tools and mainstream character of ‘money talk’ is a pragmatic choice. On the other hand, we note a strong reluctance and critical attitude towards the culture of ‘math and money’ at all levels: it is perceived as one of the main causes of social and ecological unsustainability. Several actors therefore urge for more collaborative approaches of ES valuation, e.g. to build trust between providers and beneficiaries, as monetary valuation alone is not relevant in their working context. Among the suggested solutions are the development of alternative new valuation methods and practices - amongst others using social debate and including relations between humankind and nature - as well as methods to integrate different types of values (e.g. economic, heritage, and biodiversity value) in decision making. In particular, several actors point out the necessity to account for environmental thresholds and ecological values, to consider socio-ethical values, and to deal with uncertainty, ambiguity, and complexity in decisions and actions. In the first part of this paper, we expand on the main outcomes and challenges, while ...