Emotions are currently conceptualized as ongoing temporal processes. Consistent with this view, an important target of attempts at emotion regulation are the temporal characteristics of an emotional response. The process model of emotion regulation (Gross, 1998a) distinguishes between antecedent- and response-focused emotion regulation strategies, depending on when during the unfolding emotional response they act. Two strategies that exemplify this distinction are cognitive reappraisal and expressive suppression. The present study explored the effects of the interaction between habitual engagement in reappraisal and suppression and their voluntary manipulation. Using a between-subjects design, 122 participants selected based on their self-reported habitual emotion regulation strategy (reappraisal, suppression, or both strategies without clear preference for one over the other) received instructions to engage in reappraisal, suppression, or merely watch emotion-eliciting images. Chronometric analyses of emotion-related psychophysiological measures (startle reflex modulation, corrugator electromyography, and skin conductance) were conducted in order to further characterize the differences in the time course of these two strategies during the down-regulation of negative emotion. As expected, instructions to reappraise resulted in lower unpleasantness and arousal ratings, as well as less overall corrugator electromyographic activity, compared to instructions to suppress. No differences between instruction conditions were observed on startle reflex or skin conductance. Moreover, no differences were observed in the chronometry of any of the physiological measures. Habitual emotion regulation style had no direct effect on any of the dependent variables, and it did not interact with instruction condition. The implications for the study of the chronometry of emotion regulation are discussed.