The productivity of crops can be significantly hindered by a multitude of adverse environmental and soil conditions. Among these, drought and soil salinity are the most prevalent stressors. Given the limited availability of arable land and the persistent pressure of a growing population in many developing countries, it is crucial that crop yields are not compromised on any cultivable land. Developing crop varieties that are resistant to drought and salinity stress is therefore of great importance. However, several challenges have limited the exploitation of genetic resistance, including the lack of (i) clear definitions of the level of stress that affects crop productivity, (ii) reliable screening procedures for identifying genotypes that exhibit stability of performance under stress conditions, and (iii) a thorough understanding of the processes that directly and indirectly contribute to resistance. This book provides a comprehensive overview of drought and salinity stress, addressing these challenges and offering valuable insights for students and researchers in the field of crop breeding and stress resistance. The author, a leading expert in the field, has contributed extensive knowledge and practical experience to this publication. This book serves as an essential reference for anyone seeking to improve their understanding of drought and salinity stress and breeding approaches for achieving resistance to these stressors.