RATIONALE, AIMS AND OBJECTIVES: Six years ago, the Supreme Court judgement in Montgomery v Lanarkshire changed medical law. It introduced a new patient-based standard of care for the communication of treatment risks and alternatives, rejecting the doctor-based standard that had long governed all aspects of medical negligence. This is the first systematic review to analyse the literature on Montgomery. Our aim is to appraise and synthesize the literature on Montgomery's impact on medicine and the law and to identify areas for further academic enquiry and implications for professional guidance and training. METHODS: Searches were run in Medline, Embase, PsycINFO, Web of Science, Scopus, Westlaw UK, HeinOnline, and LexisNexis. Two reviewers screened papers. Extracted data was analysed and discussed by an interdisciplinary team. PRISMA guidelines were followed. RESULTS: Of the 1134 papers identified, 100 met the inclusion criteria. These papers revealed significant disagreement on four core sets of issues, focusing on Montgomery's impact on: (1) legal and professional duties; (2) medical practice; (3) the patient experience; and (4) litigation. The first set addresses whether the case actually changed doctors' legal and professional duties, the relationship between GMC guidance and medical law, and the boundaries of Montgomery. The second explores whether the decision has incentivized defensive medicine, its resource implications, and doctors' knowledge of it. The third concerns whether and how the decision has promoted patient autonomy and involvement in their own care. The fourth focuses on whether the case has caused an increase in litigation. CONCLUSIONS: Despite the abundance of legal and medical literature on Montgomery, many issues remain unresolved. Empirical research is required for many of the questions. Doctrinal analysis informed by medical knowledge is also required to assess whether Montgomery may have unrecognized ramifications-for example, whether it will require the disclosure of risks associated with diagnostic uncertainty, where doctors advise patients without performing procedures.