The workshop ¿Dynamics and Structure of vortices¿ was held in the Clö ?tre des P¿enitents in Rouen,France on the 27th and 28th April,1999. Our understanding of the structure and dynamics of vortices has improved considerably during the last few years,mainly thanks to progress in turbulence research,where these structures have been shown to play an important role. The aim of this French workshop was to gather theoreticians,computational researchers and experimentalists to illuminate various aspects of this sub ject. We wanted on the one hand to present the state of art,and on the other hand to collect the most recent contributions on the structure and dynamics of vortices. This volume presents 22 articles corresponding to seminars and presen- tions given during this workshop. The ?rst three articles correspond to general presentations: A. Babiano presents the two-dimensional aspects of vortices; S. Huberson and O. Daube give a review on numerical methods applied to vortical ?ow; and M. Rossi presents theories of vortex instability. The following 19 papers correspond to presentations given by the parti- pants on their research subjects related to experimental,numerical or theore- cal aspects of vortices. Many of these studies are tied to related ?elds,such as turbulence,aerodynamics,wakes,geophysics,mixing,particles dynamics ... The scienti?c committee of the workshop,A. Babiano,A. Maurel,P. Pet- jeans and M. Rossi thank the CNRS for ?nancial support through the Groupe de Recherche ¿Turbulence¿ and the Groupe de Recherche ¿M¿ ecanique fon- mentale des ?uides g¿eophysiques et astrophysiques¿,and also the Association Fran¿ caise de M¿ ecanique.