Forest management planning is often challenged by the need to address contrasting preferences from several actors. Participatory approaches may help integrate actors’ preferences and demands and thus address this challenge. Workshops that encompass a participatory approach may further influence actors’ opinions and knowledge through social interaction and facilitate the development of collaborative landscape-level planning. Nevertheless, there is little experience of formal assessment of impacts of workshops with participatory approaches. This research addresses this gap. The emphasis is on the development of an approach (a) to quantify actors’ preferences for forest management models, post-fire management options, forest functions, and ecosystem services; (b) to assess the impact of participatory discussions on actors’ opinions; and (c) to evaluate the effect of social interaction on the actors’ learning and knowledge. The methodology involves a workshop with participatory approach, matched pre- and post-questionnaires, a non-parametric test, the Wilcoxon Signed-rank test for paired samples, and a self-evaluation questionnaire.We report results from an application to a joint forest management area in Vale do Sousa, in North-Western Portugal. Findings suggest that workshop and participatory discussions do contribute to social knowledge and learning about forest management models. Actors debated alternatives that can address their financial and wildfire risk-resistance concerns. Also, during the participatory discussions, actors expressed their interest in multifunctional forestry. These findings also suggest an opportunity to enhance forest management planning by promoting landscape-level collaborative forest management plans that may contribute to the diversification of forest management models and to the provision of a wider range of ecosystem services. However, more research is needed to strengthen the pre- and post-questionnaire approach, giving more time to actors to reflect on their preferences, to improve methods for quantifying social learning and to develop actors’ engagement strategies.