The objective of this study was to examine the risks for lung cancer associated with lifestyle characteristics of smoking in a developing country where lung cancer is the first cause of mortality by cancer in men, tobacco propaganda is freely allowed, and there are no restrictions operating for smoking. The design was a case-control and hospital-based study. Two hundred men with lung cancer and 397 hospital controls were interviewed. Odds ratio (OR) for current smokers was 8.5, whereas former smokers displayed an OR of 5.3. The risk increased with duration of smoking and with the number of cigarettes smoked per day. The attributable risk for smoking was 85%. Smokers of black tobacco and more than 24 cigarettes/day showed a risk of 12.9 regarding non-smokers, and of 15.5 for 40 or more years duration of smoking. The proportion of cases diagnosed as adenocarcinoma was higher than the proportion of squamous cell carcinoma.