In the vast body of literature related to French schwa behavior, prosodic factors are sometimes mentioned, but never systematically studied. This paper proposes to investigate how the topological organization of a sequence influences schwa behavior. The empirical base for this study is extracted from the PFC (Phonologie du Français Contemporain) corpus where 20 speakers have been systematically coded for prosodic elements. In addition to obvious geographical differences, we show a clear distinction between so-called optional schwas in monosyllables and in polysyllables. This contrast will impact on the phonological analysis, favoring two distinct underlying representations.