IntroductionIn the UK, the National Cancer Plan (2000) requires every cancer patient’s care to be reviewed by a multidisciplinary team (MDT). Since the introduction of these guidelines, MDTs have faced escalating demands with increasing numbers and complexity of cases. The COVID-19 pandemic has presented MDTs with the challenge of running MDT meetings virtually rather than face-to-face.This study aims to explore how the change from face-to-face to virtual MDT meetings during the COVID-19 pandemic may have impacted the effectiveness of decision-making in cancer MDT meetings and to make recommendations to improve future cancer MDT working based on the findings.Methods and analysisA mixed-methods study with three parallel phases:Semistructured remote qualitative interviews with ≤40 cancer MDT members.A national cross-sectional online survey of cancer MDT members in England, using a validated questionnaire with both multiple-choice and free-text questions.Live observations of ≥6 virtual/hybrid cancer MDT meetings at four NHS Trusts.Participants will be recruited from Cancer Alliances in England. Data collection tools have been developed in consultation with stakeholders, based on a conceptual framework devised from decision-making models and MDT guidelines. Quantitative data will be summarised descriptively, and χ2tests run to explore associations. Qualitative data will be analysed using applied thematic analysis. Using a convergent design, mixed-methods data will be triangulated guided by the conceptual framework.The study has been approved by NHS Research Ethics Committee (London—Hampstead) (22/HRA/0177). The results will be shared through peer-reviewed journals and academic conferences. A report summarising key findings will be used to develop a resource pack for MDTs to translate learnings from this study into improved effectiveness of virtual MDT meetings.The study has been registered on the Open Science Framework (https://doi.org/10.17605/OSF.IO/D2NHW).