We report the results from two experiments investigating how referential context information affects native and non-native readers’ interpretation of ambiguous relative clauses in sentences such as The journalist interviewed the assistant of the inspector who was looking very serious. The preceding discourse context was manipulated such that it provided two potential referents for either the first (the assistant) or the second (the inspector) of the two noun phrases that could potentially host the relative clause, thus biasing towards either an NP1 or an NP2 modification reading. The results from an offline comprehension task indicate that both native English speakers’ and German and Chinese-speaking ESL learners’ ultimate interpretation preferences were reliably influenced by the type of referential context. In contrast, in a corresponding self-paced-reading task we found that referential context information modulated only the non-native participants’ disambiguation preferences but not the native speakers’. Our results corroborate and extend previous findings suggesting that non-native comprehenders’ initial analysis of structurally ambiguous input is strongly influenced by biasing discourse information.