Synthesis of both inorganic and polymer materials performed in the presence of surfactant assemblies leads to meso- or nanostructured systems where the order of the self-organizing complex fluid is templated into an otherwise non-structured medium. In this review both the control of mesoporosity as well as of outer form in the nanometer region by special surfactant systems is summarized. (C) 2001 Elsevier Science Ltd. All rights reserved.