We investigated the production of subject relative clauses (SRc) in Italian pre-school children with Specific Language Impairment (SLI) and age-matched typically-developing children (TD) controls. In a structural priming paradigm, children described pictures after hearing the experimenter produce a bare noun or an SRc description, as part of a picture matching task. In a sentence repetition task, children repeated SRc. In the priming paradigm, children with SLI produced SRc after hearing the experimenter use SRc with the same or different lexical content; the magnitude of this priming effect was the same as in TDC. However, children with SLI showed a smaller cumulative priming effect than TDC. Children with SLI showed superior SRc performance in picture-matching than in sentence repetition. We propose that children with SLI have an abstract representation of SRc that can be facilitated by prior exposure, but exhibit impaired implicit learning mechanisms.