This study analyses the case of a gifted child (9;6 year) with autism spectrum disorder (ASD) who had a particularly high verbal IQ (146) and a specific cognitive, linguistic, and metalinguistic profile. A description of some salient behavioral characteristics of the child is provided. A metalinguistic ability test assessing metagrammatical, metasemantic, and metaphonological abilities and a metaphor comprehension test were administered. Both tests place high value on justifications of responses, which permits investigators to grasp different levels of metalinguistic awareness. The child gave poor metalinguistic responses in subtests assessing metasemantic abilities, contrary to subtests assessing metagrammatical and metaphonological abilities. These discrepant results are interpreted in terms of this child’s specific difficulty with ‘open’ linguistic systems, such as semantics, in spite of his high ‘closed’ language capabilities. The discussion highlights the importance of assessing the meta-level of the verbal competencies of gifted children with ASD.