RESULTS: We included 138 cases and 183 controls, of which 50 (27%) with interstitial lung diseases, 46 (25%) patients with pulmonary tuberculosis, 43 (24%) with pneumonia, 33 (18%) with pulmonary embolism and 11 (6%) with ear, nose and throat ailments. The rate of exposure to wood smoke was higher in cases vs controls, 144 and 88 hour-years (p < 0.05). Exposure to wood smoke as a dichotomous variable was not associated to the development of lung cancer, odds ratio 1.03 (95% CI 0.66-1.61). The OR for wood smoke exposure in hour-years were 1.02 (95% CI 1.00-1.00) p = 0.019. Risk of lung cancer increased linearly with hour-years of cooking with a wood stove, we observed an OR of 2.6 (2.6 (95% CI 1.05-6.44) for individuals exposed to > 100 hour-years compared with those exposed to < 100 hour-years. The association between exposure to wood smoke persisted after adjusting for sex, smoking, socioeconomic status and housing with asbestos sheet roof.