The 1st millennium ce in the Iberian peninsula was characterized by a continuous exchange of people, goods, food, technology, etc. which led to the transformation of agriculture and the introduction of new crops there. This paper presents the archaeobotanical evidence of the plants that were introduced there during the Roman and medieval periods. Cereals such as Secale cereale (rye), Pennisetum glaucum (pearl millet) and Oryza sativa (rice) appeared for the first time in the archaeological record together with new fruit taxa, Prunus persica (peach), Morus nigra (black mulberry), Prunus armeniaca (apricot), Cydonia oblonga (quince), Mespilus germanica (medlar) and Citrus species, enriching the diet of the Iberian people. There were also fibre plants such as Cannabis sativa (hemp) that are now first recorded. The paper provides the first records of these taxa while awaiting further research that can offer more detailed information on whether some of them may also have been present in earlier periods.