Background Rapid response systems (RRS) have been recommended as a strategy to prevent and treat deterioration in acute care patients. Questions regarding the most effective characteristics of RRS and strategies for implementing these systems remain. Aims The aims of this study were to (i) describe the structures and processes used to implement a 2-tier RRS, (ii) determine the comparative prevalence of deteriorating patients and incidence of unplanned intensive care unit (ICU) admission and cardiac arrest prior to and after implementation of the RRS, and (iii) determine clinician satisfaction with the RRS. Method A quasi-experimental pre-test, post-test design was used to assess patient related outcomes and clinician satisfaction prior to and after implementation of a 2-tier RRS in a tertiary metropolitan hospital. Primary components of the RRS included an ICU Outreach Nurse and a Rapid Response Team. Prevalence of deteriorating patients was assessed through a point prevalence assessment and chart audit. Incidence of unplanned admission to ICU and cardiac arrests were accessed from routine hospital databases. Clinician satisfaction was measured through surveys. Results Prevalence of patients who met medical emergency call criteria without current treatment reduced from 3% prior to RRS implementation to 1% after implementation; a similar reduction from 9% to 3% was identified on chart review. The number of unplanned admissions to ICU increased slightly from 17.4/month prior to RRS implementation to 18.1/month after implementation (p = 0.45) while cardiac arrests reduced slightly from 7.5/month to 5.6/month (p = 0.22) but neither of these changes were statistically significant. Staff satisfaction with the RRS was generally high. Conclusion The 2-tier RRS was accessed by staff to assist with care of deteriorating patients in a large, tertiary hospital. High levels of satisfaction have been reported by clinical staff.