Introduction: It is postulated that negative ruminations perpetuate insomnia symptoms by increasing arousal. Less is known about the role of positive rumination. In this study, we set out to test the association between positive and negative ruminations and subjective sleep and ask whether reappraisal and suppression moderate the relationship between rumination types and subjective sleep reports. Methods: 354 participants (59% women), ages 18-50, responded to online questionnaires regarding symptoms of insomnia (Insomnia Severity Index [ISI]), Emotion Regulation Questionnaire that provides separate scales for Reappraisal and Suppression, Negative Rumination (Ruminative Response Scale), Positive Rumination and Dampening (Responses to Positive Affect questionnaire), and general health and demographics.Results: All three rumination types significantly correlated with ISI (Negative Rumination: R=.567; Positive Rumination: R=-.128; Dampening: R=.519). The primary hypothesis was tested using six separate moderation models, where rumination type, emotion regulation style, and an interaction term were predictors and ISI as the outcome variable. The interaction terms of Negative Rumination with Reappraisal (β=-0.03) and Suppression (β=-0.07) were not significant; the interaction terms of Positive Rumination with Reappraisal (β=0.2) and Suppression (β=-0.17) were significant; and the interaction terms of Dampening with Reappraisal (β=-0.11) and Suppression (β=0.10) were significant. Discussion: Positive Rumination weakly and negatively correlated with ISI, but the combination with Reappraisal was associated with worse sleep. By contrast, Dampening was associated with worse subjective sleep, an effect attenuated by both emotion regulation strategies. Finally, Negative Rumination may be a more powerful regulator of emotion, unaffected by attempts to regulate the emotion.