Selective mutism (SM) is a rare anxiety disorder that compromises children's daily life during critical periods of early development. Because school is a prime context for the manifestation of the disorder, the aim of this study was to investigate the quality of the student-teacher relationship and its effects on behavior and work, and on social and relational skills. The sample consisted of 75 children--15 were affected by SM, with 60 in the control group--and 15 teachers. The results showed greater difficulty on the teacher's part to establish a relationship based on affective closeness with a child affected by SM, compared to that with unaffected children. Nevertheless, an encouraging picture emerges of the inclusion and integration of the child with SM among peers and therefore in the class group.