There is a pressing need to improve the ability to identify individuals at risk for nonsuicidal self-injury (NSSI; e.g., cutting or burning oneself); unfortunately, beyond prior NSSI, there are few powerful longitudinal predictors of NSSI. The present study addressed this limitation by investigating the ability of a novel factor--low aversion to self-cutting stimuli--to longitudinally predict NSSI in 49 individuals with a history of self-cutting. Results revealed that both low implicit and explicit aversion to self-cutting stimuli were significantly associated with future NSSI (rs = .32-.51), and that these associations were unique from several other theoretically important predictors, including prior NSSI, number of NSSI methods, implicit identification with self-cutting, self-prediction of future NSSI, emotion dysregulation, and therapy status. These findings are consistent with the notion that instinctive barriers (e.g., aversion to NSSI stimuli, pain) dissuade most people from engaging in NSSI, and that the erosion of these barriers may facilitate NSSI.