This study examines the discourse basis for referent accessibility and its relation to the choice of referring expressions by children with Autism Spectrum Disorder (ASD) and typically developing children. The aim is to delineate how the linguistic and extra-linguistic context affects referent accessibility to the speaker. The study also examines the degree to which accessibility effects are modulated by cognitive factors such as working memory capacity. In the study, the contrast levels between the referent and a competitor (one contrast/two contrasts) and the syntactic prominence of the referent (subject/object position in the preceding question) were manipulated in an elicited production task. The results provide evidence that the referring expressions of children with ASD correlate with the discourse status of referents to a similar extent as in typically developing controls. All children were more likely to refer with lexical NPs to referents that contrasted on two levels with a highly prominent competitor, compared to referents that contrasted on one level. They were also more likely to produce pronouns for referents previously mentioned in the subject than the object position. The effect of both discourse factors was modulated by the age and working memory capacity of the children with and without ASD. Accordingly, the study suggests that children with ASD do not generally differ from children with typical development in their referential choices when the discourse status of a referent allows them to model the referent's accessibility from their own discourse perspective in a way that is modulated by working memory capacity.