Description/Overview: Nurses are critical to improving patient outcomes but continuing shortages of registered nurses nationally and internationally, coupled with increased demands for care, mean that a different approach to nurse staffing may be necessary. One strategy is to add nursing support workers to hospital staffing. In Australia these workers are often referred to as Assistants in Nursing (AINs), and their addition to the acute care workforce in Western Australia (WA) provided an opportunity to explore the impact of their introduction. The role and tasks undertaken by AINs varies significantly across services (Duffield et al., 2014), and over time, increased patient care demands have blurred role boundaries between regulated (registered, licensed) and unregulated workers (Spilsbury et al., 2011). The role and tasks undertaken by AINs therefore varies considerably across services (Duffield et al., 2014), and there is limited literature describing the types of tasks that regulated nurses delegate to nursing support. In addition, while there is substantial evidence that the reduction of registered nursing staff in acute care environment is associated with negative patient and nurse outcomes (Duffield et al., 2011; Roche et al., 2012), the impact of adding nursing support workers is not well explored. This project examined the impact of adding AINs on patient outcomes (morbidity, mortality, quality of emotional care); staff outcomes (intention to remain in the job, absenteeism); and the work environment (time spent in patient care, relationships with medical staff, staff experiences, leadership and support of workers). The findings suggest that although adding AINs did not lead to improvements in patient outcomes, it did lead to increases in the direct care provided and redistribution of tasks amongst nurses, and the positive perceptions of this staffing model amongst regulated nurses. However, consideration must be given to the ways in which AINs are integrated into the work environment, and the functions and role they play in direct patient care. The findings will provide an evidence base for policy makers and hospital executives to plan and implement optimum nurse staffing.