The present study focused on (hypo)manic symptoms and their relations to temperament and rumination on positive affect (R-PA). As predicted, R-PA (including dampening, emotion-focus and self-focus) was associated with (hypo)manic symptoms, with high levels of dampening, emotion-focus and self-focus predicting higher levels of (hypo)manic symptoms. R-PA also contributed to the prediction of depressive symptoms over and above rumination on negative affect (including brooding and reflection), with high levels of brooding and dampening and low levels of emotion-focus predicting higher levels of depressive symptoms. Aspects of temperament (high PA, high NA, low EC and PAxNA) were also associated with (hypo)manic symptoms. Ruminative response styles were also predicted by temperament. Finally, mediational analyses showed that all R-PA scales were mediators of the PA-(hypo)mania relation.