This three volume set LNCS 6352, LNCS 6353, and LNCS 6354 constitutes the refereed proceedings of the 20th International Conference on Artificial Neural Networks, ICANN 2010, held in Thessaloniki, Greece, in September 2010. The 102 revised full papers, 68 short papers and 29 posters presented were carefully reviewed and selected from 241 submissions. The second volume is divided in topical sections on Kernel algorithms – support vector machines, knowledge engineering and decision making, recurrent ANN, reinforcement learning, robotics, self organizing ANN, adaptive algorithms – systems, and optimization.