In this review we focus on complexes of positively charged chitosan. Particular attention will be put on the thermodynamic driving forces governing the co-assembly with surfactants and on the resulting struc- tures. The main focus is on what structural control can be exerted in sur- factant/chitosan mixtures and how by that control the properties of such systems for applications can be tailored. By analyzing the behavior of chitosan mixtures with cationic, anionic and nonionic surfactants as well as with phospholipid vesicles, some aspects common to all system will be pointed out.