Accessible summary: A positive ward social climate or atmosphere can help prevent aggression and improve patient outcomes in old age psychiatry inpatient settings. The study of staff perceptions of social climate took place in three old age psychiatry inpatient units in Melbourne, Australia. Clinical staff respondents, comprising mainly mental health nurses, perceived the social climate of the units was generally positive, though there were some concerns about patient and staff safety. Respondents held a less favourable view of how patients cared about each other but a more favourable disposition about how staff cared about patients. Patient aggression occurs in old age psychiatry and is contrary to their recovery and to the well-being of staff. A favourable social climate can contribute to a reduction in aggression. The aim of this study was to examine the perceptions of clinical staff about the social climate of acute old age psychiatry inpatient units. Eighty-five clinicians were recruited from these facilities. They completed a survey questionnaire about the social climate or ward atmosphere of inpatient units. The findings showed that, to some extent, respondents' perceived patient cohesion and mutual support were evident, units were perceived somewhat positively as safe environments for patients and staff, and the ward climate helped meet patients' therapeutic needs. Overall, clinicians were somewhat positive about the social climate of the units, and this has implications for the perception of aggression in old age psychiatry inpatient settings. As there is a direct relationship between social climate and aggression, clinicians should consider adopting a broad-based, person-centred approach to the promotion of a favourable social climate in old age psychiatry inpatient settings.