This paper examines the nature of the process involved in optional schwa elision in French. More specifically, it aims at testing whether this process is gradual or categorical, on the basis of an analysis of the distribution of the duration of over 4000 schwas extracted from a large corpus of continuous speech. The distribution observed is bimodal, with absent schwas (at 0 ms duration) on one side, and realized schwas on the other side, the two groups being separated by a small gap in the distribution. Realized schwas present cases of strong temporal reduction, but this reduction does not show a continuous pattern toward zero duration, as would be predicted if schwa elision was the end-point of a gradual reduction process. Different interpretations of this distribution are discussed.