Multidisciplinary teams (MDTs) have been recommended as a key part of best cancer care for 25 years. Here, we set out the functions and approaches of MDTs and review their impact. Although the literature is patchy in quality, MDTs contribute to improving cancer care and outcomes. They must be well organized, efficient, and well led; work with sound and timely information; and communicate well within the team and with their patients. Patients need carefully prepared information to help them share in the decision-making process. MDTs will be improved by a series of ongoing innovative developments. Increasing information from molecular pathology will increase the precision of their decisions, although the technologies remain expensive and may not be accessible in all countries for some time. New point-of-care testing technologies will improve the quality and timeliness of testing. Good informatics is essential to deliver the information to patients and the MDT. MDTs should be research active, delivering clinical trials, and this should improve outcomes for all of their patients. Patient engagement and empowerment in MDTs should improve patient satisfaction and outcomes. Patient-reported outcome measures will improve MDTs' insights into their patients' problems and symptoms and can improve patient outcomes.