Flue-cured tobacco is an important commercial crop, which is highly sensitive to the wet conditions. An experiment was conducted with different periods of waterlogging (0, 24, 48, 72 and 96 h) at flower bud initiation stage to study its effect on gas exchange parameters, activity of antioxidative enzymes, yield and quality of flue-cured tobacco. The gas exchange parameters viz., photosynthetic rate, stomatal conductance and transpiration rate and soluble proteins decreased with increase in waterlogging period. The activities of peroxidase, polyphenol oxidase and catalase as well as superoxide dismutase showed variation under waterlogging condition which protects the cells from reactive oxygen species generated under waterlogging. With increase in period of waterlogging yield was reduced by 23, 43, 76 and 82 % due to waterlogging for a period of 24, 48, 72 and 96 h, respectively. Quality constituents viz., nicotine and reducing sugars decreased with increase in the period of waterlogging at all leaf positions on the plant. The results showed that tobacco plants tried to counteract the adverse effects of waterlogging by enhancing the activity of superoxide dismutase.