In order to elucidate the still controversial structure and properties of mixed lecithin-bile salt micelles, we performed static and dynamic light scattering experiments over a wide range of scattering angles. The data were interpreted by applying concepts from polymer and colloid physics and incorporating the effects of polydispersity and interparticle interactions. We demonstrate that a self-consistent interpretation of the data at concentrations above the mixed micellar phase limit is possible in terms of a structural model of wormlike micelles. At concentrations below the micellar phase limit, mixed lecithin-bile salt vesicles form spontaneously and coexist with wormlike micelles in an extended coexistence region.