Multidisciplinary management tumor boards are now conducted worldwide for the management of patients with cancer. Studies evaluating their influence on decision making and patient outcome are limited; however, single-center studies have reported significant changes in diagnosis and treatment plans. A survey from Arabic countries showed widespread use and reliance on tumor boards for decision making. A recent multi-institutional survey of veteran affairs (VA) hospitals in the United States found limited association between the presence of tumor boards and care and outcomes. The Cancer Care Outcomes Research and Surveillance Consortium looked at the association between tumor board features and measures of quality of care. Results of overall survival among the patients of these physicians participating in tumor boards is ongoing, but preliminary results are outlined along with a recent ASCO survey of international members on the presence, utilization, and influence of tumor boards in this article. Tumor boards allow for implementation of clinical practice guidelines and may help capture cases for clinical trials. Efforts to improve preparations, structure, and conduct of tumor boards, research methods to monitor their performance, teamwork, and outcomes are outlined also in this article. The concept of mini-tumor boards and more efficient methods for MDM in countries with limited resources are also discussed. In suboptimal settings, such as small community hospitals, rural areas, and areas with limited resources, boundaries in diagnosis and management can be overcome, or at least improved, with tumor boards, especially with the use of video-conferencing facilities. Studies from the United Kingdom showed that special training of multidisciplinary teams (MDT) led to better team dynamics and communication, improved patient satisfaction, and improved clinical outcome. The weight of the benefits versus the time and effort spent to improve efficiency, patient care, and better time management in the United States and in the international oncology community is also reviewed in this article.