Individuals who present to emergency departments with self-harm are at elevated risk of further self-harm and suicide, and these risks are yet higher among patients who self-cut. Repetitive self-injury has previously been explained using a behaviourist approach focussing on operant conditioning, but we propose that the increased risk of self-harm repetition among those who present with self-cutting is at least partly mediated by pre-existing psychological risk factors. Several studies show that those who present with self-cutting differ from intentional overdose patients on demographic, psychiatric and social factors, but, based on findings from community-based studies, we hypothesise that there may be additional psychological differences that may also be associated with increased repetition risk. We conducted a small-scale cohort study of 29 self-harm patients presenting to A&E and compared theoretically-derived psychological variables between 8 self-cutting and 21 overdose patients. Those presenting with self-cutting scored significantly higher on hopelessness and lower on non-reactivity to inner experience and generally had a more vulnerable profile than those presenting with overdose. These findings support our hypothesis that the association between self-cutting and prospective repetition is at least partly due to pre-existing psychological vulnerabilities that increase both the likelihood of engaging in self-cutting as a method of self-harm and the likelihood of subsequent repetition of self-harm. Existing evidence suggests that self-cutting is a risk factor for repetition of self-harm, and it is possible that reducing and preventing repetition among these patients can be achieved by implementing psychological interventions to reduce hopelessness and increase tolerance of emotional distress.