Research suggests that self-injurious thoughts and behaviors (SITBs) may function as maladaptive emotion regulation strategies. One psychophysiological index of emotion regulatory capacity is respiratory sinus arrhythmia (RSA). The temporal course of RSA responsivity to a stressor may be characterized by basal RSA, RSA reactivity to stressor, and RSA recovery post-stressor. RSA has been linked to both internalizing and externalizing symptoms in adolescents, but little is known about the relation between RSA and SITBs. Initial research has shown a cross-sectional relation between lower basal RSA and greater RSA reactivity to a sad mood induction and self-injury. To date no prospective research on the relation between RSA and SITBs exists. The current study aims to investigate the prospective relation between RSA and SITBs in a community sample of 108 adolescents (Mage=12.82, SDage=0.82, 53.70% female). At the initial laboratory visit (T1), participants completed an unsolvable anagram stressor task, during which RSA (basal, reactivity, and recovery) was measured. SITBs were assessed at T1 and at the 6-month follow-up (T2). Results indicated basal RSA and RSA reactivity did not significantly predict engagement in SITBs between T1 and T2. Poorer RSA recovery from the stressor task at T1 did significantly predict engagement in SITBs between T1 and T2, over and above depressive symptoms and lifetime history of SITBs. This suggests that adolescents with poor ability to regulate physiologically following a stressor may turn to maladaptive emotion regulation strategies like SITBs.