The 12th International Workshop on Electromagnetic Nondestructive Evaluation (ENDE'07) was held from the 19th to the 21st of June 2007 at the Wolfson Centre for Magnetics at Cardiff University, Cardiff, United Kingdom. The aim of this annual workshop is to bring together engineers and scientists from universities, research institutions and industry to discuss and exchange the latest ideas and findings in basic research and development as well as industrial applications of electromagnetic non-destructive evaluation. This publication contains the proceedings of the workshop. In this book you will find a variety of topics on both theoretical and experimental aspects of nondestructive evaluation in eddy currents, magnetic measurements, magnetic flux leakage, Barkhausen methods, new methods and inverse problems for crack detection.