What is known on the subject?: Nurses in mental health inpatient settings use a range of methods to try and help service users who self-harm Harm-reduction approaches are intended to help service users reduce the impact of their self-harm rather than simply to prevent them self-harming Harm-reduction techniques might be helpful for people who cut themselves because there are some clear ways harm can be minimized such as providing advice about cutting No one has previously tried to measure whether harm-reduction techniques are more or less acceptable to mental health practitioners and service users than traditional methods. What the paper adds to existing knowledge?: The paper describes the development of the Attitudes to Self-cutting Management scale. It met the criteria required of a good measurement tool. Each method of managing self-cutting has a unique acceptability profile Harm-reduction methods like advising on wound care and providing a first aid kit are endorsed by nurses and former service users Nurses providing sterile razors or remaining present during self-cutting attract more divergent opinions but are preferred to seclusion and restraint. What are the implications for practice?: Nurses should talk through the approaches to management with service users and agree which techniques are preferred. Abstract: Introduction Harm-reduction approaches for self-harm in mental health settings have been under-researched. Aim To develop a measure of the acceptability of management approaches for self-cutting in mental health inpatient settings. Methods Stage one: scale items were generated from relevant literature and staff/service user consultation. Stage two: A cross-sectional survey and statistical methods from classical test theory informed scale development. Results/Findings At stage one, N = 27 staff and service users participated. At stage two, N = 215 people (n = 175 current mental health practitioners and n = 40 people with experience of self-cutting as a UK mental health inpatient) completed surveys. Principal components analysis revealed a simple factor structure such that each method had a unique acceptability profile. Reliability, construct validity and internal consistency were acceptable. The harm-reduction approaches “advising on wound care” and “providing a first aid kit” were broadly endorsed; “providing sterile razors” and “maintaining a supportive nursing presence during cutting” were less acceptable but more so than seclusion and restraint. Discussion The Attitudes to Self-cutting Management scale is a reliable and valid measure that could inform service design and development. Implications for practice Nurses should discuss different options for management of self-cutting with service users. Harm-reduction approaches may be more acceptable than coercive measures.