Recent research showed that cognitive emotion regulation (ER) both increases activity in the dorsolateral prefrontal cortex (DLPFC) and decreases striatal responsivity to monetary rewards. Using a mixed monetary incentive delay/memory task as well as functional magnetic resonance imaging, we tested in healthy subjects whether ER effectively attenuates striatal reward encoding during the anticipation of reward (€1.00 vs. €0.05 reward cues) as well as subsequent target reaction times (RTs), which are an indicator of motivation to obtain reward. ER significantly diminished feelings of pleasant anticipation and slowed down €1.00 target RT. At the neural level, ER increased activity in the DLPFC and attenuated reward encoding in the left putamen. Analyses of psychophysiological interaction revealed that DLPFC activity correlated more positively with putamen activity during €0.05 than during €1.00 reward trials. Furthermore, parametric modulations showed that anticipatory left putamen activity correlated with target RT during nonregulation. No such correlation could be observed during ER, suggesting that ER had abolished preparatory target RT encoding. Our results provide evidence that ER can attenuate behavioral and striatal measures of reward-related motivation and motor preparation. Furthermore, the present findings suggest that the DLPFC might contribute to successful regulation of reward via increased promotion of low-reward responses.