Background: There is no commonly accepted definition of the term self-harm, and there is an ongoing debate about whether or not it should include acts of attempted suicide. The use of this language in clinical practice has not previously been explored. Aims: To investigate if, and how, practitioners distinguish between acts of self-harm and attempted suicide, and present any implications for practice. Method: We conducted semistructured interviews with a random sample of 18 frontline practitioners from 10 mental health wards and completed a thematic analysis of interview data. Results: Most participants described self-harm and attempted suicide as distinct behaviors. Characteristics of the act, disclosures of intent, and the level of distress observed were commonly used to differentiate between self-harm and attempted suicide. Very few participants believed that people who self-harm may also feel suicidal. Practitioners confidently described two different behaviors, yet self-harm and attempted suicide were often conflated, revealing the challenges and complexities associated with the separation of these acts in clinical practice. Limitations: Clinicians working in other settings or disciplines may have different views. Participants' accounts may not be an accurate representation of what happens in practice. Conclusion: This study adds to a body of evidence which argues against the dichotomous separation of these behaviors into acts of suicidal and nonsuicidal self-harm.Our findings suggest there is no common understanding of the boundaries between self-harm and attempted suicide among frontline clinicians. The language currently used, and consequent practice, particularly with regard to risk assessment, is problematic. Efforts should be made to operationalize terms around suicidal behavior and to incorporate these into training for clinical staff.