Organic semiconductors enable a wide range of applications such as solar cells, thin-film transistors, sensors and thermoelectrics. Processing, the resulting nanostructure and device performance are intimately linked. This symposium aims to bring together key researchers in this field to discuss the main challenges towards the widespread application of organic electronics. Processing of organic semiconductors from solution promises fabrication of large-area opto-electronic devices on flexible substrates at low-cost. The choice of processing parameters including thermodynamic and rheological variables, the use of additives and the surface chemistry of the substrate critically influences the resulting nanostructures. In turn, the precise nanostructure determines the opto-electronic properties of an organic semiconductor thin film. Although tremendous progress has been made recently in developing new processing schemes and many applications are now at hand, with some of them on the verge of commercialization, great challenges still have to be faced, mainly regarding (1) the precise control of nanostructures, (2) the development of in-situ characterization tools, (3) a fundamental understanding of key structure-processing-property relationships, and (4) the long-term stability of materials and devices.