This article describes a participatory action research study aimed at improving the care of older people with mental health needs who are cared for in an older people's unit of a general hospital in the UK. A multicollaborative and interpretivist action research approach was adopted, whereby the researchers, managers, clinical staff, patients, and carers came together to identify the problems and their potential solutions. Focus groups, interviews, and observations of care were used to collect the data and to inform the action and development cycles and a grounded theory approach was used to analyze these data and to develop theoretical descriptions regarding the dynamics that occur within this setting. Four overarching themes were identified as contributing to the theoretical understanding of this type of care: cultural knowledge, contextual reality, giving care, and coping with "the problem". Understanding the theoretical elements is of importance in assisting nurses, and others, to consider care that is person-centred.