This article presents the results of 21 years of field-walking in the Crépy-en-Valois area. The coherent nature of these prospections supports a preliminary proposition for the dating of human occupation in a hitherto little known sector. Emphasis is laid on the evolution of Gallo-Roman occupation between the 1st and 4th centuries. The pitfalls inherent in the method must be taken into account when assessing the results set out here.