Onshore wind farms play an important role in realizing the 2030 climate targets. According to the Climate Agreement, onshore energy production should be increased to 35 TWh by 2030. This means that up to 600 additional wind turbines should be developed, which is a challenging task. The development of onshore wind farms often meets the resistance of local residents. This opposition can, inter alia, result in project delays or cancellations. Citizen participation is a widely discussed manner to prevent and deal with local opposition. In this thesis, exploratory qualitative analysis is conducted to address the following research question: How does citizen participation influence decision-making processes of four selected Dutch onshore wind farms? The present research focuses on the interaction between the most important actors within the participation process: local residents, the government, and the wind farm initiators. A multiple-case study is conducted to analyse the decision-making processes and to answer the main research question. Four Dutch cases are analysed; Jaap Rodenburg II, Nij Hiddum-Houw, Windplanblauw and Wind Farm Moerdijk. First, each case was studied separately by conducting four within case studies. Afterwards, the analyses have been compared in a cross-case study. The theoretical framework, Teisman's Rounds Model and Contextual Interaction Theory (CIT), were used to code qualitative data in a thematic analysis. The data is collected by conducting semi-structured interviews conducted and studying policy documents. This way, citizen participation, decision-making processes, and the actors' roles could be described meticulously. The findings of the analyses are presented in the Rounds Model and the CIT. The Rounds Model is used to graphically represent the decision-making processes and the role of the actors. Since the Rounds Model pays little attention to contextual factors and governance levels affecting the decision-making process, the CIT contributes to the Rounds Model. As mentioned before, the CIT and the Rounds Model functioned as a theoretical framework to conduct the cross-case study. The Rounds model facilitated a comparison of the four participation and decision-making processes. The rounds model has provided information about the interrelation of the decisions made, the relation between actors, the intensity of the participation rounds and the most influential moments at a glance. The CIT is used to study the most important participation rounds more in-depth and provided information about governance and other contextual factors influencing those events. The combination of the two models led to a broad understanding of the decision-making processes and an in-depth insight into the factors of influence. The analyses have shown that citizen participation is used to equally distribute benefits and burdens of winds farms, reduce nuisance, convince the responsible authority that the interests of local residents are considered, improve the wind farm design, and reduce local opposition. Multiple forms of citizen participation are found in the decision-making processes: wind farm cooperatives and associations, options for financial investment, community funds, design workshops, surveys about the wind farm layout, working groups and advisory boards. In all of the cases studies, local opposition led to a more intensive citizen participation process. The different forms of participation, as described above, have led to the re-location of wind turbines, a reduction of the turbine height, additional nuisance reducing measures, additional financial benefits and once even to a totally new wind farm layout. Several factors were discerned to stimulate the decision-making process. Especially co-ownership, representativeness of the participating local residents and early engagement have improved the citizen participation process. Additionally, a stringent policy and an independent party to advise local residents during the participation process can facilitate efficient decision-making. Therefore, it is recommended to 1) the initiators and the responsible authority to immediately start the citizen participation process, 2) actively invite local residents of all surrounding districts to the participation process, 3) provide local residents with an option for co-ownership, 4) the municipalities and provinces to define clear participation in policy documents on before, and 5) to ensure local residents have an independent advisor during the participation process. Lastly, several subjects for further research are identified. First of all, it would be interesting to combine or compare the findings of the four cases with findings from other studies developed by different parties. Here, additional knowledge can be collected that can be used to investigate potential influencing factors further as identified here; the influence of the responsible authority and the room for negotiation. Above all, it should be studied how to ensure a representation of local residents and how to interest local residents to participate in an early stage. And, how will participation influence the decision-making process in the new situation: where the Climate Agreement, the RES and the new Environment and Planning Act are guiding.