Background: Cardiopulmonary arrest may result in high mortality rate in hospitals where the rapid response team is not implemented. A rapid response system can recognize patients at high risk of cardiopulmonary arrest and provide the needed medical management to prevent further deterioration. The rapid response system has shown a dramatic reduction in mortality rate and cardiopulmonary arrest. Objective: To evaluate the effectiveness of the rapid response team (RRT) implementation in reducing the mortality rate, number of cardiopulmonary arrests, and number of ICU admission. Design: A pre- and post-rapid response team system implementation. Setting: Four tertiary private hospitals in Saudi Arabia. Patients: A total of 154,869 patients in the 3-year before rapid response system period (January 2010 to December 2012) and a total of 466,161 during the 2.5-year post-RRT implementation period (January 2014 to June 2016). Results: Results indicated that ward nurses activated RRT more often than physicians (1104 activations [69%] vs. 499 activations [31%]), with cardiovascular and respiratory abnormalities being the most common triggers. Serious concern about the patient condition by the ward staff was the trigger for 181 (11.29%) activations. The RRT provided a variety of diagnostic and therapeutic interventions. Most patients cared for by RRT were admitted to ICU 1103 (68.81%), and the rest 500 (31.19%) were managed in the ward. After the implementation of the RRT project, the hospital mortality rate dropped from 7.8 to 2.8 per 1000 hospital admission. Hospital cardiopulmonary arrest rate has dropped from 10.53 per 1000 hospital admissions to 2.58. Rapid response team implementation also facilitated end-of-life care discussions. Conclusion: Implementation of the RRT project has shown a dramatic reduction in the total ICU admissions, average ICU occupancy rate, total hospital mortality, and total ICU mortality. These findings reinforce the evidence that RRT implementation is effective in reducing hospital mortality and cardiopulmonary arrest rates in addition to other outcomes related to healthcare quality.