Forests are an important source of natural and environmental resources, and also a source of economic activity. Public attitudes towards the forests have rarely been studied, and this stufy focus on that topic aiming at: (a) describing the attitude towards the forest of the residents near the forest areas in Portugal, describing its socio-demographic correlates; (b) to test the hierarchic relationship between ecologic values, attitudes towards the forest and use of the forest, following the work of McFarlane and colleagues (e.g., McFarlane & Boxall, 2003); and (c) testing the moderating role of attitudinal ambivalence (Conner & Sparks, 2002) in the association between attitudes and behaviour related to the forests. A sample of residents living close to forests was collected in this study. The participants had low levels of education and were old, compared to the rest of the portuguese population. Results show that the general attitude towards the forest is quite positive, recognizing the positive environmental and economic impacts of the forests and supporting the expansion of the forest. In terms of the socio-demographic determinants, more positive attitudes were found among: the younger and more educated participants; the ones with higher levels of economic resources; people living in the North; the ones working in areas related to the forestry. To test the hierarchic model of values, attitudes and behaviour the mediation procedure proposed Baron & Kenny (1986) was used. Ecological values are associated with the use of the forest but this relationship is partially mediated by the attitude towards the forest. Finally, the role of attitudinal ambivalence was tested. Although the level of ambivalence was low, results show that the behaviour of ambivalent participants is inconsistently associated to attitudes. This study, with a national sample, assesses the positive attitude towards the forests in Portugal and stresses its determinants. The role of demographic variables, values and the link to behaviour is now more clear, as well as the role of ambivalence in the association to behaviour.