The Third National Survey The Portuguese, the Environment and the Territory intends to continue and ensure that a process of observation and monitoring of the changes and evolution of the Portuguese opinion on environmental and land use issues is carried out. A decade after the beginning of this process of continuous and systematic observation with the first “Portuguese Survey on the Portuguese and the Environment” (1997), it is the objective of this third Survey to follow the monitoring of the representations, attitudes, values and practices of the Portuguese regarding the environment and to the territory, through the application of a new questionnaire to a representative sample of the Portuguese population. The analysis will take into account the marked diversity of Portuguese society and the social dynamics that run through it, due to socio-cultural, economic and geographical variables.