The American Cancer Society (ACS) is a nationwide, community-based voluntary health organization dedicated to eliminating cancer as a major health problem by preventing cancer, saving lives, and diminishing suffering through research, education, advocacy, and service. This organization has over two million volunteers nationwide and is one of the oldest and largest voluntary health agencies in the United States. Its headquarters is based in Atlanta, Georgia and they have state divisions and more than three thousand four hundred local offices.

The American Cancer Society's international mission concentrates on capacity building in developing cancer societies and on collaborations with other cancer-related organizations throughout the world in carrying shared strategic directions.

The American Cancer Society fights cancer through research, education, advocacy, and service. The research programs of the ACS are aimed in determining the causes of cancer and to support efforts to prevent and cure the disease. It is the largest source of private, nonprofit cancer research funds in the United States, second only to the federal government in total dollars spent. The research program focuses primarily on peer-reviewed projects initiated by beginning investigators working in leading medical and scientific institutions across the country. Educational efforts of the ACS include tobacco control, relationship between diet and physical activity and cancer, sun safety, and comprehensive school health education. The society offers programs to help educate the public about cancer risks, early detection methods, and prevention. Knowing the facts about cancer can save lives. What you eat and drink, how you live, where you work, all these factors can affect the risk for cancer and primary cancer prevention means taking the necessary precautions to prevent the occurrence of cancer. The society's advocacy efforts work in concert with research, education and service initiatives to strengthen the nation's law, regulations, and programs in a way that will increase federal funding for cancer research, help more people benefit from advances in prevention, early detection and treatment, make it easier for patients to navigate the health care system, and improve the quality of life of cancer patients, survivors, and their families. Because cancer takes a toll on the person diagnosed as well as family and friends, the society offers support and service programs to try to lessen the impact. These programs cover wide range of needs, from connecting patients with other survivors to providing a place to stay when treatment facilities are far from home.

The American Cancer Society, Inc. is governed by two national groups with distinctive roles: the National Assembly and the National Board of directors. The voting members of both are volunteers from medical and lay communities. The society takes its mission seriously and therefore works to protect resources entrusted to it by the public. An appropriately structured system of organizational governance ensures proper checks and balances of the input of appropriate experts in decision-making and strategic oversight of comprehensive nationwide operations.