Introduction: Multiple national organizations have identified a need to incorporate more evidence-based medicine in emergency medical services (EMS) through the creation of evidence-based guidelines (EBGs). Tools like the Appraisal of Guidelines for Research and Evaluation (AGREE) II and criteria outlined by the National Academy of Medicine (NAM) have established concrete recommendations for the development of high-quality guidelines. While many guidelines have been created that address topics within EMS medicine, neither the quantity nor quality of prehospital EBGs have been previously reported. Objectives: To perform a systematic review to identify existing EBGs related to prehospital care and evaluate the quality of these guidelines using the AGREE II tool and criteria for clinical guidelines described by the NAM. Methods: We performed a systematic search of the literature in MEDLINE, EMBASE, PubMED, Trip, and guidelines.gov, through September 2018. Guideline topics were categorized based on the 2019 Core Content of EMS Medicine. Two independent reviewers screened titles for relevance and then abstracts for essential guideline features. Included guidelines were appraised with the AGREE II tool across 6 domains by 3 independent reviewers and scores averaged. Two additional reviewers determined if each guideline reported the key elements of clinical practice guidelines recommended by the NAM via consensus. Results: We identified 71 guidelines, of which 89% addressed clinical aspects of EMS medicine. Only 9 guidelines scored >75% across AGREE II domains and most (63%) scored between 50 and 75%. Domain 4 (Clarity of Presentation) had the highest (79.7%) and domain 5 (Applicability) had the lowest average score across EMS guidelines. Only 38% of EMS guidelines included a reporting of all criteria identified by the NAM for clinical practice guidelines, with elements of a systematic review of the literature most commonly missing. Conclusions: EBGs exist addressing a variety of topics in EMS medicine. This systematic review and appraisal of EMS guidelines identified a wide range in the quality of these guidelines and variable reporting of key elements of clinical guidelines. Future guideline developers should consider established methodological and reporting recommendations to improve the quality of EMS guidelines.