The current diagnostic criteria for the autism spectrum disorder (ASD) include the possibility to specify concomitant language difficulties. Purpose: Our main aim was to explore whether children with ASD-Level 1 (ASD-L1) present difficulties in the acquisition of structural language, as little work has been done in this regard so far. As a secondary aim we evaluated the degree to which the potential language impairment in ASD is directly associated with their social communication deficits or it represents a distinct deficit. Methods: To further clarify the nature and characteristics of putative language difficulties in ASD-L1, we evaluated language skills in 89 children and preadolescents diagnosed with ASD-L1, and a group of typically developing participants (TD). All of them were between 8 and 13 years old and had similar socioeconomic backgrounds. Results: Children with ASD-L1 obtained lower scores than those in TD group in repeating sentences, in finding the semantic relationships between words, and in applying word structure rules (morphology). Congruently, the core language standard score was lower in the ASD-L1 group, and the proportion of language delay was significantly higher in the ASD-L1 group than in the control group. Conclusion: Language scores were associated with autistic traits; thus, language performance in ASD-L1 is closely related to autistic symptoms. These results are discussed according to the literature on linguistic deficits in ASD-L1 and their relations with phonological working memory.