The purpose of this study was to describe and discuss students' perceptions and attitudes toward cultural differences as reflected in the processes of intercultural communication in culturally diverse classrooms. We chose a multiple-case study design to interview students from diverse cultural backgrounds enrolled in multicultural elementary (n = 14) and secondary (n = 30) schools in the province of Alicante, Spain. Results showed that communication among cultures is complex and can be characterized by feelings of isolation, need for social acknowledgment, and attitudes of avoidance. In addition, differences in attitudes toward culturally diverse students were found between elementary and secondary school respondents, with secondary interviewees being less positive than elementary interviewees. Results also showed evidence of stereotypes about the learning potential of students from immigrant origin, leading to the need to model and change students' representation and attitudes toward cultural differences. Teacher training in diverse methods are recommended in order to enhance the internalization of concepts and the ability to confront fears, misconceptions and misinformation of students.