It is well documented that tobacco use is strongly associated with a number of malignancies. There are over 60 carcinogens in tobacco smoke that lead to development of cancers in the lung and at least 19 other sites. Strong evidence indicates smokers can reduce their risk for developing cancer by quitting smoking. Even after developing cancer, patients may benefit from quitting smoking. Accumulating evidence indicates quitting vs. continued smoking after cancer diagnosis is associated with 30% to 50% lower risk of death and disease progression. Several mechanisms have been suggested by which smoking can reduce survival in patients with cancer; cigarette smoke contains many carcinogens and mutagens that can directly affect tumor cells and increase their proliferation and migration, smoking can impair the immune response to malignant growth, smoking can affect the response to and complications from some cancer treatments and accelerate other illnesses including cardiovascular and other chronic diseases in patients with cancer. However, up to 50% of patients who were smoking before a cancer diagnosis continue to smoke during treatment. Healthcare professionals can optimize the management of cancer if they understand the impact of smoking cessation on cancer treatment share this information with patients and provide support to quit. Smoking cessation interventions should be offered to cancer patients in a systematic way, using evidence-based guidelines. Pharmacological interventions combined with cognitive and behavioral interventions currently provide the best opportunity for long-term cessation of smoking in cancer patients and should be part of the patient navigation process. This session will focus on: • The importance of smoking cessation after a cancer diagnosis – The evidence on different cancers and outcomes • The evidence of the economic benefit of the healthcare systems • Initiatives from Canada, USA, and Europe • A patient's view/experience