This book constitutes the refereed proceedings of the 11th International Conference on Engineering Applications of Neural Networks, EANN 2009, held in London, GB, on August 27-29, 2009.

The 47 revised full papers were carefully reviewed and selected from many submissions. The following diverse topics were discussed: reducing urban concentration, entropy topography in epileptic electroencephalography, phytoplanktonic species recognition, revealing the structure of childhood abdominal pain data, robot control, discriminating angry and happy facial expressions, flood forecasting and assessing credit worthiness.