A method for monitoring fatigue cracks in thin-walled shell-structures using piezoelectric polyvinylidene fluoride (PVDF) films is presented. By means of a spatially resolved measurement, it allows the simultaneously localization of the crack tip and determination of the K - factors by solving the resulting inverse problem. In previous publications ,  only the K I - factor as well as the position of the crack tip could be determined with sufficient accuracy but not the K II- factor. Therefore, the concept will be tested and verified using the example of a crack in an infinite plate. From that we deduce some recommendations for the electrode placement and the solution of the inverse problem. In addition, a first experiment of a cracked aluminum specimen is reported.© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.