This volume of Advances in Intelligent and Soft Computing contains accepted papers presented at the 8th International Conference on Computational Intelligence in Security for Information Systems (CISIS 2015) and the 6th International Conference on European Transnational Education (ICEUTE 2015). These conferences were held in the beautiful and historic city of Burgos (Spain), in June 2015.The aim of the 8th CISIS conference is to offer a meeting opportunity for academic and industry-related researchers belonging to the various, vast communities of Computational Intelligence, Information Security, and Data Mining. The need for intelligent, flexible behaviour by large, complex systems, especially in mission-critical domains, is intended to be the catalyst and the aggregation stimulus for the overall event.After a through peer-review process, the CISIS 2015 International Program Committee selected 43 papers, written by authors from 16 different countries. In the case of 6th ICEUTE conference, the International Program Committee selected 12 papers (from 7 countries). These papers are published in present conference proceedings, achieving an acceptance rate of about 39%.The selection of papers was extremely rigorous in order to maintain the high quality of the conference and we would like to thank the members of the Program Committees for their hard work in the reviewing process. This is a crucial process to the creation of a high standard conference and the CISIS and ICEUTE conferences would not exist without their help.