The study aiming to determine the effect of different irrigation regimes and water stress imposed at different growth stages on water use and leaf yield of flue-cured tobacco plant (Nicotiana tabacum L.), was carried out during the period of 2000-03. The field trials were conducted on a silty loam Entisol soil, poor in organic matter and rich in potassium on the fields of the Atatürk Soil and Water Resources Research Institute in Kırklareli. A randomised complete block design with three replications was applied and K-326 Virginia tobacco cultivar was used in the experiment. Three known stages of the plant, vegetative (V), yield formation (F) and ripening (R), were considered and a total of 14 (including rain-fed) irrigation treatments were applied. All the experimental treatments were irrigated on the same day in each growth stage with the amount of water required to fill the 0-90 cm soil depth to field capacity, and three levels of water amount reductions (0, 40 and 60%) were applied at each development stage. A single irrigation was applied during the second part of the vegetative stage, while subsequent water applications were at the 50 and 70% depletion level during the yield formation and ripening stages, respectively. Results of the 3-year study show that either total irrigation water amounts and number of applications, or leaf yields are closely related to precipitation rate and distribution during the growing year. While the seasonal irrigation amounts applied in the adequate irrigation treatment (VFR) were greater (945 and 815 mm respectively in the drier experimental years of 2000 and 2001), they were much lower (587 mm) during the rainy year of 2003. The highest leaf yields in the range of 5170-6050 kg ha À1 were obtained from the fully irrigated programme (VFR), from treatments with 40% reduction in irrigation water amount at any stage (V 1 FR; VF 1 R, VFR 1 ) and irrigation programme (FR) including omitted irrigation at vegetative stage and fully irrigated during the next two stages. It was also determined that close linear relationships exist between seasonal evapotranspiration rate and leaf yield, and seasonal evapotranspiration deficit and relative yield reduction, during each of the experimental years. Copyright