Many are apprehensive about mental health care, which potentially affects engagement in recovery processes as well as health outcomes. This article introduces a tool to assess fear of adverse mental health treatment experiences from the client's perspective. In a sample of 656 adults receiving mental health services at community agencies, this study is an initial exploration into the validity of a scale assessing fears associated with commonly experienced coercive or disorganized interventions. Factor analyses supported the construct validity of the 10-item Fear of Adverse Treatment Experiences Scale. It significantly discriminates based upon service characteristics, gender, history of victimization, and past experiences with coercive or disorganized interventions, with higher levels of fear reported by users of traditional mental health services, former inpatients who had their voluntary admission status changed, males, people with history of childhood abuse, and people with certain forms of criminal justice involvement.