ABSTRACT: Nonsuicidal self-injury (NSSI), the deliberate, self-inflicted damage of bodily tissue without the intent to die, is associated with various negative outcomes. Although basic and epidemiologic research on NSSI has increased during the last 2 decades, literature on effective interventions targeting NSSI is still emerging. Here, we present a comprehensive, systematic review of existing psychological and pharmacological treatments designed specifically for NSSI, or including outcome assessments examining change in NSSI.We conducted a systematic search of PsycINFO, MEDLINE, and ERIC databases to retrieve relevant articles that met inclusion criteria; specifically, uncontrolled and controlled trials that 1) presented quantitative outcome data on NSSI, and 2) clearly differentiated NSSI from suicidal self-injury (SSI). Consistent with the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, definition of NSSI, we excluded studies examining populations with developmental or intellectual disabilities, or with psychotic disorders.Several interventions appear to hold promise for reducing NSSI, including dialectical behaviour therapy, emotion regulation group therapy, manual-assisted cognitive therapy, dynamic deconstructive psychotherapy, atypical antipsychotics (aripiprazole), naltrexone, and selective serotonin reuptake inhibitors (with or without cognitive-behavioural therapy). Nevertheless, there remains a paucity of well-controlled studies investigating treatment efficacy for NSSI.Structured psychotherapeutic approaches focusing on collaborative therapeutic relationships, motivation for change, and directly addressing NSSI behaviours seem to be most effective in reducing NSSI. Medications targeting the serotonergic, dopaminergic and opioid systems also have demonstrated some benefits. Future studies employing controlled designs as well as a clear delineation of NSSI and SSI will improve knowledge regarding treatment effects.