The focus prominence rule (FPR) predicts that speakers articulate their utterances in such a way that the nuclear stress falls within the focus domain (¿Qué compró Juan? ‘What did John buy?’ → Juan compró [una bicicleta]F ‘John bought [a BIKE]F’ / #Juan compró [una bicicleta]F ‘John bought [a bike]F’). To examine the consequences of the FPR for focus interpretation, we carried out a perception experiment using oral production data produced by Argentinean speakers. Two groups of hearers representing either the Argentinean or the Peninsular variety of Spanish were tested. We examined whether the focus-background partition assigned by hearers to (contextless) SVO sentences coincides with the focus-background partition under which the sentences had originally been produced. The results show that the hearers’ interpretations coincide with the original focus-background partition in 70% of the responses and that the accuracy rate strongly depends on three variables: focus type (contrastive (CF) > information focus (IF)), focused constituent (subject > direct object), and variety spoken by participants (Argentinean Spanish > Peninsular Spanish). The accuracy ranges from 94% ([subject]CF, Argentinean participants) to 43% ([object]IF, speakers of Peninsular Spanish). Besides the three above-mentioned factors, we discuss whether stress placement (and sentence form more generally) can be seen as focus marking devices in Spanish. We argue that sentence form is best viewed as a filter, which rules out (or makes improbable) certain focus-background partitions. However, contextual cues are often necessary to identify the actual focus-background partition of a sentence.