In spite of the general acceptance of GM technology among farmers, consumers, mainly in Europe, have traditionally shown more concern about biotechnology applied to food. The aim of this paper is to analyse the consumer behaviour in Spain in relation to GM food, taking into account the new labelling regulation. From a telephone survey conducted all over Spain, we analyse the knowledge degree, attitudes and purchasing intention of Spanish consumers towards GM food. Results indicate that knowledge about Gm food in Spain is lower than in other European countries or in USA. Moreover, only those consumers who show a higher objective knowledge about GM food are more likely to buy such products.