This book constitutes the refereed proceedings of the 8th International Conference on Quantum Interaction QI 2014 held in Filzbach Switzerland in June/July 2014. The 19 papers together with 20 invited keynotes presented in this book were carefully selected from 22 submissions. Quantum Interaction has developed into an emerging interdisciplinary area of science combining research topics in fundamental issues semantic and memory decision making games politics and social aspects non-locality and entanglement.