The Implicit Prosody Hypothesis assumes that differences in individual languagesÂ’ attachment preferences for syntactically ambiguous sentences are due to the languagesÂ’ different prosodic systems. For example, when a relative clause modifies a complex noun phrase (NP1 NP2 RC), a prosodic break after NP1 is said to trigger a low attachment interpretation, while a break after NP2 triggers high attachment. English and Spanish participants read aloud sentences of this type, but showed no correlation between prosodic phrasing pattern and attachment choice. Both English and Spanish readers pronounced the majority of sentences with the strongest prosodic break following NP2. However, responses to comprehension questions immediately following each production showed that Spanish speakers preferred a high attachment interpretation, while English speakers preferred low attachment. Our findings provide evidence against a prosodic account of overall attachment preferences for this construction and provide insights into the mechanisms of reading aloud.