(a) Improve nurse knowledge of and confidence in responding to clinical deterioration through implementation of the Modified Early Warning Score tool and (b) improve nurse ability to react to patient deterioration in a timely manner.Recognition of clinical deterioration in hospitalized inpatients often occurs far after those signs initially present. The Modified Early Warning Score has been shown to assist with recognition earlier in the deterioration process.Eighty-five nurses participated in a simulation-based intervention to implement the Modified Early Warning Score into their rural hospital. Group classroom sessions and individual high-fidelity simulation experiences were provided for participants. Twenty-nine nurses also participated in self-confidence and knowledge assessment testing.The simulation-based intervention significantly improved nurse knowledge (t = 4.029, p < .01) and self-confidence (t = 3.698, p = <.01). Chart reviews found a 34.1% increase in nurse action taken in response to signs of clinical deterioration.Current study found that the Modified Early Warning Score tool as taught through a simulated patient experience is useful to prevent unrecognized deterioration.Suggests that a simulation-based intervention is effective for teaching and evaluating post-licensure nurses on acute clinical deterioration in inpatients.