Objective To inform improvement in the process and outcomes of care by describing the views and practices of psychologists working in public mental health services (PMHS) regarding provision of physical healthcare for consumers. Method Cross‐sectional qualitative study employing a theoretical model of behaviour (capability, opportunity, motivation, and behaviour; COM‐B model). Data collected in semi‐structured interviews with maximum diversity sample of 29 psychologists were analysed using the framework approach. Results Participants were cognisant of the need to improve physical health among people with severe mental illness (SMI); they endorsed, to varying extents, the obligation of PMHS and potential of psychologists, collectively to contribute to this goal through provision of interventions targeting health behaviours. Within a context in which psychology was generally underutilised, practice varied widely, ranging from avoidance to integration of physical health care in clinical practice. In combination, mixed‐messages about service priorities, role ambiguity, competing demands, and concern about adequacy of knowledge and skills inhibited attention to physical health for most participants, particularly those working in generic case management roles. Some highly motivated psychologists, most of whom worked in specialised teams within which attention to physical health was normative, made and capitalised on opportunities to develop and apply skills to enable consumers to change behaviour and improve physical health. Conclusion While further education and training will enhance capability and motivation of psychologists, realisation of the potential contribution to improvement in physical health of people with SMI will fundamentally, require assertion of the identity and value of the profession within mental health services. Ensuring optimal use of scarce resources necessitates careful consideration of deployment of discipline specific expertise, and clarity about responsibilities of psychologists within teams.