Objectives: To evaluate the effects on quality and efficiency of implementation of the advanced practice provider in critical care. Data Sources: PubMed, Embase, The Cochrane Library, and CINAHL were used to extract articles regarding advanced practice providers in critical care. Study Selection: Articles were selected when reporting a comparison between advanced practice providers and physician resident/fellows regarding the outcome measures of mortality, length of stay, or specific tasks. Descriptive studies without comparison were excluded. The methodological quality of the included studies was rated using the Newcastle-Ottawa scale. The agreement between the reviewers was assessed with Cohen's kappa. A meta-analysis was constructed on mortality and length of stay. Data Extraction and Synthesis: One-hundred fifty-six studies were assessed by full text. Thirty comparative cohort studies were selected and analyzed. These compared advanced practice providers with physician resident/fellows. All studies comprised adult intensive care. Most of the included studies showed a moderate to good quality. Over time, the study designs advanced from retrospective designs to include prospective and comparative designs. Data Synthesis: Four random effects meta-analyses on length of stay and mortality were constructed from the available studies. These meta-analyses showed no significant difference between performance of advanced practice providers on the ICU and physician residents/fellows on the ICU, suggesting the quality of care of both groups was equal. Mean difference for length of stay on the ICU was 0.34 (95% CI, -0.31 to 1.00; I 2 = 99%) and for in hospital length of stay 0.02 (95% CI, -0.85 to 0.89; I 2 = 91%); whereas the odds ratio for ICU mortality was 0.98 (95% CI, 0.81-1.19; I 2 = 37.3%) and for hospital mortality 0.92 (95% CI, 0.79-1.07; I 2 = 28%). Conclusions: This review and meta-analysis shows no differences between acute care given by advanced practice providers compared with physician resident/fellows measured as length of stay or mortality. However, advanced practice providers might add value to care in several other ways, but this needs further study.