The 20th International Conference on Artificial Neural Networks (ICANN 2010) will be held in the city of Thessaloniki, Greece. It is an annual event, organized since 1991 by the European Neural Network Society (ENNS) in co-operation with the International Neural Network Society and the Japanese Neural Network Society. Since the first conference in Helsinki, ICANN has been established as a premier event. It provides a great discussion forum for the academic and industrial community on achievements not only related to artificial neural networks but to various other topics of artificial intelligence as well. More specifically, ICANN 2010 endeavours to address new challenges, share solutions and discuss future research directions in neural networks, learning systems, computational intelligence, and real-world applications. Moreover, it aims in promoting the significant benefits that can be derived by the use of neural networks and novel, innovative applications are appreciated.