Introduction:
Smoking and passive smoking shows a strong correlation with highly increased risk for lung cancer. 87 percent of lung cancer deaths are due to smoking. Cancer diagnosis is a strong motivation of smoking cessation for patients. Our aim is the clinical significance of smoking cessation after cancer diagnosis and smokers characteristics that influence positively or negatively the success of smoking cessation.

Material and Methods:
1020 smokers were examined, 83 with a history of cancer and 937 without cancer. They attended a 12 weeks program with counselling and first line medical treatment of smoking cessation. Exhaled carbon monoxide measured in every visit. Determination of dependence on nicotine, the level of mobilization in terms of trying to quit smoking and deprivation during the quit attempt evaluated.

Results:
The Continuous Abstinence Rate (CAR) among cancer patients was 55.47% and in non-cancer patients was 67.02%. Sex and educational level did not affect the success of cessation. However, in cancer smokers found that the existence of severe dependence, contrary to the general population, does not affect smoking cessation.

Conclusions:
Smoking cessation in patients with cancer is accompanied by significant success, although this outcome is poorer compared with non-cancer smokers. Cancer patients must follow well-organized smoking cessation programs as soon as diagnosis is made, in order to have a successful and prolong smoking cessation.