Recently processed syntactic information is likely to play a fundamental role in online sentence comprehension. For example, there is now a good deal of evidence that the processing of a syntactic structure (the target) is facilitated if the same structure was processed on the immediately preceding trial (the prime), a phenomenon known as structural priming. However, compared with structural priming in production, structural priming in comprehension remains relatively understudied. We investigate an aspect of structural priming in comprehension that is comparatively well understood in production but has received little attention in comprehension: the cumulative effect of structural primes on subsequently processed sentences. We further ask whether this effect is modulated by lexical overlap between preceding primes and the target. In 3 self-paced reading experiments, we find that structural priming effects in comprehension are cumulative and of similar magnitude both with and without lexical overlap. We discuss the relevance of our results to questions about the relationship between recent experience and online language processing.