Power asymmetries affect the governance of natural resources but are rarely considered explicitly in ecosystem services research, which often overlooks the diversity of actors and their interactions. In this paper, we propose an innovative and easily replicable method to analyze two types of power asymmetries, using social network analysis and a power typology which distinguishes between influence and domination. We apply this method to a network of actors involved in the governance of eight ecosystem services in the Peruvian Andes. The results reveal substantial power asymmetries, of different types. Indirect managers of ecosystem services had higher influence and domination than the direct managers and beneficiaries. Businesses showed significantly lower influence than members of civil society, non-governmental organizations, and the public sector (state or decentralized organizations, public enterprises). Compared to other actors, members of the public sector had significantly higher domination, especially national actors. Domination and influence relationships strongly increased conflict probability, along with difference of domination score between two actors. A better interdisciplinary understanding of the determinants of power asymmetries can make the governance of socio-ecological systems more sustainable.