This paper explores the acquisition of personal reference terms in Thai, a language with a highly complex personal reference system. Two separate studies were conducted for this paper, each featuring two groups of participants: children with typical development (TD) and children with autism spectrum disorders (ASDs). In each study, the participants were asked to complete two tasks on personal reference terms: a production task and a comprehension task. Overall, children with ASD performed on par in production, in terms of overall communicative success. However, an important finding was that they demonstrated a tendency toward pronoun avoidance, being less likely than children with TD to use deictic first-person pronominal forms. Instead, they preferred to use fixed referential terms for self-reference, contrasting with the children with TD's preference for personal pronouns. The performance of children with ASD was significantly poorer in comprehension than that of children with TD. Children with ASD were generally able to detect lexically encoded person features but struggled with the more pragmatic and socially deictic aspects of personal reference terms. The latter also posed some challenges for children with TD, albeit to a lesser extent. In this regard, our results align with previous claims in the literature that lexical presuppositions are acquired earlier than implicated presuppositions. Our findings also add various new insights in terms of both population-specific effects in a language previously unstudied in this regard and the specific ways in which aspects of implicated presuppositions, i.e., the type of content in play, give rise to particular challenges in acquisition in general and for children with ASD in particular.