This article reexamines the puzzling issue of where subjects, lexical and null, are located in Spanish and offers a novel explanation for the incompatibility of preverbal lexical subjects with fronted focussed constituents. Both SpecIP and the left periphery appear to be potential landing sites for subjects, according to discourse-pragmatic factors. Assuming that pro is a clitic, it is argued that the aforementioned incompatibility can be captured by a simple rule: SpecIP must be empty for focus fronting to occur. This is the case with pro, which adjoins to Infl, or with postverbal subjects since they remain in SpecVP. From this analysis it follows that: 1) the subject field in Spanish is less articulated than is generally assumed, 2) the differences between Spanish and other null subject languages with respect to the availability of preverbal subjets can be reduced to this rule and a different ordering of focus and topic phrases, and 3) it is unnecessary to posit two different topic positions.