Selective mutism (SM) is a rare and complex disorder associated with anxiety symptoms and speech-language deficits; however, the nature of these language deficits has not been studied systematically. A novel cross-disciplinary assessment protocol was used to assess anxiety and nonverbal cognitive, receptive language, and expressive narrative abilities in 7 children with SM and a comparison group of 7 children with social phobia (SP). The children with SM produced significantly shorter narratives than children with SP, despite showing normal nonverbal cognitive and receptive language abilities. The findings suggest that SM may involve subtle expressive language deficits that may influence academic performance and raise additional questions for further research. The assessment procedure developed for this study may be potentially useful for language clinicians.