Images by cryo-transmission electron microscopy show two types of structure in dilute aqueous mixtures of amylose (AM) and sodium dodecyl sulfate (SDS): Loose fibrous networks and unilamellar vesicles. Neither of the structures was observed in reference solutions of AM or SDS alone. It is proposed that both types of structure consist of inclusion complexes where SDS molecules are enclosed in V-type single helices of amylose. In the vesicles, the complexes are packed, by folding of the AM helices, into lamellae.