Rumination has been associated with reduced working memory and dorsolateral prefrontal cortex activity. This study explored whether single session anodal transcranial direct current stimulation (tDCS) applied to the dorsolateral prefrontal cortex and/or working memory training can transiently ameliorate working memory and down regulate state rumination. Sixty-six participants were randomly allocated to three conditions: (1) control training + tDCS, (2) working memory training + sham tDCS and (3) working memory training + tDCS. Before and after manipulation participants performed working memory tasks and state rumination was measured with self-report and heart rate variability. Participants who received real tDCS were significantly faster in switching between information in working memory than participants who received sham tDCS. No effects on self-reported state rumination were found. However, both groups receiving working memory training showed a higher increase in heart rate variability than the control training group, indicating more adaptive self-regulation.