This book contains the proceedings of the COSIT 2011 workshop on An Interdisciplinary Approach to Understanding and Processing Sketch Maps, held as part of the 10th Conference on Spatial Information Theory, which took place in the beautiful coast town of Belfast, Maine, USA, in September 2011. The six research papers making up the content of this book have been thoroughly reviewed by a program committee of internationally renowned researchers. The topics range from empirical investigations of the usage of sketch maps to algorithmic problems of processing sketch maps in geographic information systems.