Abstract: This qualitative study explores the perceptions of mental health nurses regarding assessment in an acute adult inpatient setting in Central Auckland. Fourteen mental health nurses took part in semi-structured interviews answering five open-ended questions. The analysis of data involved a general inductive approach, with key themes drawn out and grouped into four categories (roles, attitudes, skills and knowledge) in order to explore the meaning of information gathered. The outcome of the study acknowledged the importance of contextual factors such as the physical environment and bureaucratic systems, as well as values and beliefs present within the unit. The participants expressed concern that their input to assessment processes was limited, despite belief that 24-hour care and the nature of mental health nursing generally suggested that a crucial role should exist for nurses. In order for nurses to be established as central in the assessment process on the unit the study concludes that a nursing theoretical framework appropriate for this acute inpatient setting needs to be developed.