Purpose: The purpose of this study was to investigate the relationship of the grunt vocalizations to cognitive and expressive language status in children with disabilities. Children with typical development produce communicative grunts at the onset of referential word production and comprehension at 14-16 months of age and continue to use this vocalization for communication as they develop language. Method: All grunt vocalizations produced by 26 children with disabilities (mental age: 3-56 months; communicative age: 47-69 months) were identified from video-recorded seminaturalistic play sessions. Grunts were identified as accompanying effort or attention or as communicative bids. Participants were grouped as prelinguistic, emergent, language delay, and language competent based on standardized assessments of cognitive and language level. The Mann--Whitney U test (1947) compared groups to determine the relationships between grunt production and cognitive and language status. Results: As hypothesized, participants in the language delay group produced significantly more communicative grunts than those in the language competent group (W = 39, p = 0.028 < 0.05). The children with a cognitive and language level lower than 9 months (prelinguistic group) failed to produce communicative grunts. Conclusions: The results document grunt production in children with disabilities in the same contexts as typical children and support the hypothesized relationship between assessed cognition and language and communicative grunt production. These results require replication. This vocalization, if recognized in treatment, may unlock verbal communication in many nonverbal children with disabilities. Future longitudinal research should include controlled intervention to determine the potential effectiveness of building broader communicative skills on this simple vocalization.