The structure of polyelectrolyte and nanoparticle-polyelectrolyte multilayers constructed onto vesicles will be studied by Small Angle Neutron Scattering. This is an exploratory investigation and our first goal is to compare the structure of multilayers built onto fluid and curved interfaces (vesicles) with the structure of polyelectrolyte multilayers supported on solid flat substrates which are well studied. As far as we are aware, polyelectrolyte multilayers has not been built onto vesicles up to now (there is a very recent paper on vesicles decorated with one layer of polyelectrolyte, Soft Matter 201 ) and obviously these systems have not been studied previously neither by Light, X-Ray or Neutron scattering techniques.