Clinician attitudes and antipathy towards clients who engage in nonsuicidal self-injury (NSSI) are an important area of concern as these impact clinical care and formulation. This research addressed clinician beliefs and antipathy towards NSSI and investigated the impacts of these on identified functions of the behaviours. The research also explored the impacts of NSSI training, confidence in their professional abilities, professional orientation, experience, age, and gender in clinician approaches to NSSI. A sample of 245 Australian psychologists, social workers, counsellors, and youth workers completed a series of self-report surveys. The results highlighted that younger clinicians were exposed to more clients presenting with NSSI than older colleagues and reported greater confidence in recognising NSSI and differentiating it from suicidality. Higher levels of confidence were related to greater exposure to NSSI and targeted training on NSSI, regardless of practitioner background. In relation to attitudes, social workers endorsed feeling the least antipathy towards NSSI. Gender, age, years of practice, and the number of clients who had self-injured were not significantly related to antipathy. Antipathy was inversely related to an appraisal of NSSI as an intrapersonal function, yet conversely, no relationship was found between the interpersonal functional domain and antipathy. A model exploring practitioner appraisals about the function of NSSI, exposure, professional orientation, years of practice and confidence predicted a significant portion (32%) of the variance in practitioner antipathy.