This book outlines essential elements of the evaluation of health surveillance within the One Health concept. It provides an introduction to basic theoretical notions of evaluation and vividly discusses related challenges. Expert authors cover the entire spectrum of available, innovative methods, from those for system process evaluations to methods for the economic evaluation of the surveillance strategies. Each chapter provides a detailed description of the methodology required and the tools available as illustrated by practical examples of animal health or One Health surveillance evaluations in both developed and developing countries. Targeting not only scientists, including epidemiologists, but also technical advisers of decision-makers, the present work is suitable for the evaluation of any type of health surveillance system - animal, human or combined - regardless of the socio-economic context. The volume is richly equipped with practical tools and examples, which enables the reader to apply the methods described. Increasing importance of health surveillance, and threats from disease outbreaks such as the coronavirus pandemic, underline the practical relevance of this work, which will fill an important gap in the literature.