Early diagnosis of selective mutism (SM) is an important concern. SM prevalence is higher than initially thought and at least three times higher in immigrant language minority children. Although the DSM-IV precludes diagnosing SM in immigrant children with limited language proficiency (as children acquiring a second language may normally undergo a “silent period”), specific diagnostic boundaries are not clear. The specific focus of this article is, therefore, the exact circumstances in which a language minority child should be diagnosed with SM.