Abstract : Bangladesh is a high Tuberculosis (TB) burden country particularly due to the burden of drug-resistant TB. Smoking increases the risk of relapses of TB, which remains to be explored in the context of Bangladesh. This case-control study was conducted in two tertiary level hospitals in Dhaka City to determine the association between smoking habit and relapse tuberculosis (TB). The study population was the registered adult TB patients who got complete treatment within 2-5 years. Relapse and non-relapse TB cases are listed serially in the hospital record books. The relapse cases were selected randomly as case group and age-matched (±2 years) with the respondent of the case group, cured patients were included as control groups. A total of 170 respondents in each case and control groups were selected with 80% power and assuming 14% differences between cases and controls. The selected respondents who visited the respective hospitals on the scheduled day were interviewed face to face for data collection. The mean age of the participants was 39.7±11.56 years. Significantly (χ2=20.767; p=0.000) a higher proportion of the relapse cases were found among the respondents who got complete TB treatment 3 years before in comparison to that of the control group. Family size more than five, education of secondary level, two earning members in the family, past smoker, smoked more than 10 cigarettes per day and exposure to second-hand smoking were found to be significantly associated with a higher proportion of relapse cases. Regression analysis revealed that exposure to second-hand smoking and past smokers was 2.4 and 2.0 times respectively more likely to develop relapse TB. Thus, this study concluded that past smoking habit and exposure to second-hand smoking had the strongest likelihood of developing more TB relapse cases