This chapter explores how perceived misfit influences the performance of self-regulatory processes in the workplace. The authors integrate person–environment fit theory with research on self-regulation to show how misfit impairs goal setting, monitoring, and adjustment. They argue that misfit disrupts individuals’ capacity to align effort with goals, leading to resource depletion, reduced persistence, and impaired performance. The chapter develops a conceptual model in which misfit triggers negative affect and cognitive interference that weaken self-control and hinder adaptive goal pursuit. It also considers the moderating roles of individual and contextual factors such as resilience, self-efficacy, autonomy, and organisational support in shaping how employees respond to misfit. The authors propose that some individuals can use misfit experiences as feedback to recalibrate goals or craft their jobs, thereby restoring functional regulation. The framework therefore positions misfit not only as a stressor but also as a potential stimulus for learning and adaptation. By linking misfit to fundamental self-regulatory mechanisms, the chapter provides a psychological account of why misfit sometimes leads to exhaustion and failure, yet in other circumstances promotes development and renewed engagement. This integration advances understanding of the motivational consequences of misfit and its implications for individual effectiveness at work.