This study investigates the attitude and practices of GM and non-GM maize farmers in Portugal. Thirty seven GM maize farmers were interviewed representing 22.5% of the total number of GM maize notifications in the country. Additionally, 66 non-GM maize farmers were surveyed in an attempt to investigate their opinion on the Bt technology, its viability and its future. The most interesting finding is that almost half of all the surveyed maize farmers (GM and non-GM) stated that the ex ante regulations are rigid and difficult to apply. On the contrary, the ex post tort liability rules are very clear and provide the appropriate security for the continuation of the GM maize cultivation.