The present study uses an international survey composed of several scales to compare diversity and social inclusion among 164 teachers and 317 students from universities and 216 practitioners. Participants belong to four countries: Italy, Poland, Romania, and Spain (IPRS). The results illustrate the same or different perspectives of teachers, students, and practitioners about competencies for 21st-century teachers, efficient professionals in inclusive education, the program of the Master's Degree in Education for diversity and social inclusion, and the components for a curriculum adaptation in IPRS. IPRS showed a clear difference among their groups of teachers, students, and practitioners. Limitations and future directions are included.