The nature of the facilitation occurring when sentences share a verb and syntactic structure (i.e., lexically-mediated syntactic priming) has not been adequately addressed in comprehension. In four eye-tracking experiments, we investigated the degree to which lexical, syntactic, thematic, and verb form repetition contribute to facilitated target sentence processing. Lexically-mediated syntactic priming was observed when primes and targets shared a verb and abstract syntactic structure, regardless of the ambiguity of the prime. In addition, repeated thematic role assignment resulted in syntactic priming (to a lesser degree), and verb form repetition facilitated lexical rather than structural processing. We conclude that priming in comprehension involves lexically associated abstract syntactic representations, and facilitation of verb and thematic role processes. The results also indicate that syntactic computation errors during prime processing are not necessary for lexically-mediated priming to occur during target processing. This result is inconsistent with an error-driven learning account of lexically-mediated syntactic priming effects.