ABSTRACT Mobility is one of the key actions within the process of internationalising school education to develop interculturally competent pupils. The study at the heart of this paper – Developing Intercultural Competence Through Adolescents’ Mobility (DICTAM) – seeks to explore which programme design features and individual characteristics are most closely associated with the development of intercultural competence. To reach this goal, a longitudinal study (using open-ended questionnaires and the Intercultural Development Inventory) was conducted with 378 pupils from Italian secondary schools who participated in a mobility programme. Overall findings suggest that different individual characteristics and programme design variables might have a different bearing on enhancing intercultural competence. In our sample, the variables duration (longer is better) and gender (female) are the ones which more likely have a positive impact on intercultural growth.