Abstract We present theory and research on effort mobilization that is relevant for understanding the role of affect in cognitive control. We posit that cognitive control and effort are closely related and introduce motivational intensity theory and supporting empirical evidence mainly based on cardiovascular measures of effort. Most important, we discuss the role of affect in the context of effort mobilization and cognitive control from different perspectives. We first present theories predicting affective influences on effort, namely the mood-behavior-model and the implicit-affect-primes-effort model, and supporting empirical evidence. Second, we discuss further implications of the resource conservation principle highlighting the aversive aspect of effort and review evidence for the impact of value and its affective component on effort and cognitive control. Finally, we present a recent integration of the neural mechanisms underlying both effort and cognitive control. We conclude that affective processes are necessary and instrumental for both effort mobilization and cognitive control.