Background Triage is a dynamic environment in which large numbers of people can present. It presents a vulnerable assessment point, as a triage nurse must assess a patient's urgency level and analyse their health status and expected resource needs. Given the critical nature of triage, it is necessary to understand the factors contributing to patient safety. Objectives To identify and examine the factors contributing to patient safety during the triage process. Methods A systematic review of the literature was undertaken, and a thematic analysis of the factors contributing to patient safety during the triage process. PubMed, CINAHL, Web of Sciences, Science Direct, SAGE, EMBASE and reference lists of relevant studies published in English until March 2022 were searched for relevant studies. The search protocol has been registered at the PROSPERO (CRD42019146616), and the review was conducted using the PRISMA criteria. Results Out of 5366 records, we included 11 papers for thematic synthesis. Identified factors contributing to patient safety in triage are related to the emergency's work environment, such as patient assessment, high workload, frequent interruptions and staffing, and personal factors such as nurse traits, experience, knowledge, triage fatigue and work schedule. Conclusions This review shows that patient safety is influenced by the attitude, capabilities and experiences of triage nurses, the time when nurses can dedicate themselves to the patient and triage the patient without disruption. It is necessary to raise awareness among nursing administrators and healthcare professionals to provide a safe triage environment for patients. Relevance to Clinical Practice This review highlights the evidence on the factors contributing to patient safety in the triage process. Further research is needed for this cohort of triage nurses in the emergency department concerning ensuring patient safety. Patient or Public Contribution No patient or public contribution was required to design or undertake this review.