Job demands-resources (JD-R) theory is commonly used to predict employee well-being, work behaviors, and performance. This article provides a short description of JD-R theory and discusses issues and questions that have been raised regarding the theory. These issues include the differences between conservation of resources theory and JD-R theory, whether a job resource can be a job demand, the impact of job resources on strain and health, the role of hindrance and challenge job demands in JD-R theory, the relationship between job demands and resources, and the likelihood of work engagement being a redundant concept. We also discuss whether JD-R theory can be falsified, the role of personality in the theory, within- and between-person effects in JD-R theory, the question whether there is a standard JD-R questionnaire, and the existence of loss and gain spirals. Finally, we discuss the use of JD-R theory in domains other than work and answer the question whether JD-R theory is universally applicable. (PsycInfo Database Record (c) 2024 APA, all rights reserved).