Although Portugal registers a large number of protected brand names, its economic turnover is very low when compared to the other southern EUMember States. To identify and analyze the main reasons of this weak economic significance of the Portuguese quality traditional agrifood products are the main goals of this paper. The main conclusions from the data gathered in step one of the research, which main goal was to understand the main reasons why agricultural firms do not adhere to the PDO/PGI food systems, are related with several issues, namely: the economic and transactions costs of certification, the heavy bureaucracy related to the certification process, the small difference in prices between PDO/PGI products and standard products, within the same reference market, and the preferences of Portuguese consumers. According to the respondents, Portuguese consumers do not know nor socially valorize PDO/PGI products, and privilege (i) traditional/local standard products, instead of PDO/ PGI products, and (ii) proximity marketed relationships. These latter findings contribute to highlight, not only why the interviewed firms do not adhere to the PDO/PGI systems, but also why the Portuguese PDO/PGI domestic market is narrow when compared with the ones of southern EU-Member States.