The incidence of stomach cancer in India is lower than that of any other country around the world. However, in Mizoram, one of the north-eastern state of India, a very high age-adjusted incidence of stomach cancer is recorded. A hospital-based case-control study was carried out to identify the influence of tobacco use on the risk of developing stomach cancer in Mizoram. Among the cases, the risk of stomach cancer was significantly elevated among current smokers [odds ratio (OR), 2.3; 95% confidence interval (95% CI), 1.4-8.4] but not among ex-smokers. Higher risks were seen for meiziol (a local cigarette) smokers (OR, 2.2; 95% CI, 1.3-9.3). The increased risk was apparent among subjects who had smoked for >or=30 years. The increased risk was significant with 2-fold increase in risk among the subjects who smoked for >or=11 pack-years. The risk increased with increasing cumulative dose of tobacco smoked (mg). Tuibur (tobacco smoke-infused water), used mainly in Mizoram, was seemed to increased the risk of stomach cancer among current users in both univariate and multivariate models (OR, 2.1; 95% CI, 1.3-3.1). Tobacco chewer alone (OR, 2.6; 95% CI, 1.1-4.2) showed significant risk. Tobacco use in any form [smoking and smokeless (tuibur and chewing)] increased the risk of stomach cancer in Mizoram independently after adjusting for confounding variables.