Contemporary societies are increasingly multireligious, multiethnic, and multicultural, but to what extent are they ready for coexistence? This paper evaluates the competencies for intercultural and interreligious dialogue in two very different contexts: Barcelona and Melilla, two cities with great ethnic and cultural diversity, in which it is easy to have contact with people of different cultures and religions. To this end, we worked with a total of 1353 adolescents and young people, and four scales were used to evaluate intercultural and interreligious sensitivity, conflict management skills, and prejudices towards unaccompanied migrant minors. The findings suggest that in neither of these two contexts do adolescents and young people form relationships with these minors, despite accepting religious diversity and being educated at school in topics relating to coexistence and spirituality. In fact, participants showed a high level of prejudice towards this population. Implementation of more effective intervention programs in both cities is therefore recommended.