The ability to extract meaning through the use of syntactic cues, adapted from Naigles' (1990) paradigm, was investigated in Hebrewspeaking children with autism, those with specific language impairment (SLI) and those with typical language development (TLD), in an attempt to shed light on similarities and differences between the two diagnostic categories, both defined by primary language deficits. Thirteen children with autism and 13 with SLI were matched on chronological age, level of language functioning and gender, and 13 children with TLD were matched to the children in the two clinical groups according to language level, as measured by the CELF-P. Children with autism and children with TLD learned novel words using the syntactical cues in the sentences in which they were presented, whereas children with SLI experienced more difficulty, learning only that which would be expected from chance according to the binomial test. Only 4 of the 13 children with SLI (31 %) learned the new words, whereas n children with autism and 10 children with TLD learned the novel verb using syntactical cues from the sentence frame. The results are analyzed in terms of possible underlying mechanisms in language acquisition. Children with autism seem to rely on relatively intact syntactic abilities, while children with SLI seem to have marked impairment in using this mechanism in acquiring word meaning. Implications for future research and intervention with preschool children with primary language disorders are discussed.