BACKGROUND: A fast-growing body of research provides support for the role of positive emotion dysregulation in the etiology and maintenance of a wide range of psychiatric difficulties and clinically relevant behaviors. However, this work has exclusively relied on the subjective assessment of positive emotion dysregulation. Advancing research, the current study examined associations between physiological and subjective indices of positive emotional responding in the laboratory. Specifically, we explored the relation of the Difficulties in Emotion Regulation Scale - Positive (Weiss, Gratz, & Lavender, 2015) to resting heart rate variability (HRV) at high and low state positive affect intensity. METHODS: Participants were 122 individuals recruited from college and community settings (M (age) = 23.39, 84.4% female, 68.0% White). RESULTS: Findings indicated a positive relation between positive emotion dysregulation and resting HRV at high state positive affect and a negative relation between positive emotion dysregulation and resting HRV at low state positive affect. CONCLUSIONS: Results extend our understanding of the associations among subjective and physiological indices of positive emotional processes. These findings have key implications for the conduct of research on positive emotion dysregulation.