The forestry sector in Chile has an important role in the domestic economy, being the second leading export sector after the mining industry. Investments in forest plantations have grown in the last 40 years thanks to implementation of the Decree Law 701. Planted forests currently account for 17.4% of the total national forest cover. The objective of the study is to analyse non-industrial forest owners’ perceptions of positive and negative externalities of forest plantations in four less developed municipalities of the Maule Region. We implemented a literature review, the estimation of an Expert’s Response Indicator (ERI), and the implementation of an Analytic Hierarchy Process (AHP) methodology for the analysis. The results indicate that non-industrial forest owners in the four municipalities perceive the importance of each externality in a different way according to their territorial specificities. However, considering the whole study area, «CO2 sequestration», «improvement of livelihood», and «more importance of small and medium forest owners» were considered the most important positive externalities, while the most relevant negative externalities were «water shortage», «power asymmetry», and «land loss». The study encourages further research with a similar detailed analysis on stakeholders’ perceptions of plantation projects, both to revise investment features and inform local stakeholders on their real impacts.