The purpose of these meta-analyses was to quantitatively synthesize the effectiveness of simulation on student nurses’ and registered nurses’ ability to recognize and manage clinical deterioration in the acute care setting. A search of the literature resulted in 22 reports and 19 studies meeting inclusion criteria. Four random-effects analyses were conducted to examine two-group posttest and single-group pre–posttest intervention effect sizes for knowledge and performance. A total of 41 effect sizes were calculated from the data extracted. The standardized mean difference (d) for two-group posttest knowledge was d = 0.964 (p = .001) and for performance was d = 1.382 (p ≤ .001). The standardized mean difference for single-group pre–posttest knowledge was d = 1.231 (p ≤ .001) and performance was d = 1.610 (p ≤ .001). Findings indicate that simulation-based interventions have a positive effect on knowledge and performance. As simulation is increasingly used as a teaching modality in nursing, further research should aim to test standardized simulation-based education programs.