Aims and method Relational security is an important component of care and risk assessment in mental health services, but the utility of available measures remains under-researched. This study analysed the psychometric properties of two relational security tools, the See Think Act (STA) scale and the Relational Security Explorer (RSE).Results The STA scale had good internal consistency and could highlight differences between occupational groups, whereas the RSE did not perform well as a psychometric measure.Clinical implications The measures provide unique and complimentary perspectives on the quality of relational security within secure services, but have some limitations. Use of the RSE should be restricted to its intended purpose; to guide team discussions about relational security, and services should refrain from collecting and aggregating this data. Until further research validates their use, relational security measurement should be multidimensional and form part of a wider process of service quality assessment.