Introduction: Police officers' occupational patterns and their needs for health promotion are rarely addressed in police health research, partly due to the lack of specific instruments. This study describes the initial steps in developing an instrument that targets officers' lifestyles and health, utilising occupational therapy and - science.Method: The study includes 48 participants and uses an instrument development methodology. First, the construct was defined through theoretical dimensions with two focus groups. Second, items were developed and tested during cognitive interviews with 28 officers. Finally, the instrument underwent content validity testing with nine occupational therapists.Results: The instrument is based on the construct of police officers' conditions for a sustainable and healthy lifestyle. This refers to an individualised, balanced lifestyle that enables participation, choice and control, supporting healthy routines, roles and meaningful occupations across various life domains shaped by social, occupational and physical environments over time. All domains encompass aspects of working and personal life, and the balance between them.Conclusion: The instrument's psychometric properties, representativeness and feasibility need to be continuously evaluated. Subsequently, occupational therapists and human resource personnel may use it to promote police officers' sustainable lifestyles and life balance as an assessment and a self-reflection tool.