Psychiatric hospitalization can cause significant distress for patients. Research has shown that to cope with the stress, patients sometimes resort to self-harm. Given the paucity of research on self-harm among psychiatric inpatients, a better understanding of transdiagnostic processes as predictors of self-harm during psychiatric hospitalization is needed. The current study examined whether coping styles predicted self-harm after controlling for commonly associated factors, such as age, gender, and borderline personality disorder. Participants were 72 patients (mean age = 39.32 years, SD = 12.29, 64% male) admitted for inpatient treatment at a public psychiatric hospital in Sydney, Australia. Participants completed self-report measures of coping styles and ward-specific coping behaviors, including self-harm, in relation to coping with the stress of acute hospitalization. Results showed that younger age, diagnosis of borderline personality disorder, and higher emotion-oriented coping were associated with self-harm. After controlling for age and borderline personality disorder, higher levels of emotion-oriented coping were found to be a significant predictor of self-harm. Findings were partially consistent with hypotheses; emotion-oriented but not avoidance-oriented coping significantly predicted self-harm. This finding may help to identify and provide psychiatric inpatients who are at risk of self-harm with appropriate therapeutic interventions.