This trial was realized in the greenhouses of Uludag University Yenisehir Vocational School in Bursa province of Turkey between 2009 and 2010 to investigate effects of water deficit on yield and quality parameters of tomato during four crop growth stages. In this trial, fourteen irrigation treatments in four growth periods (vegetative, flowering, yield formation and ripening) of tomato (Lycopersicon lycopersicum L. var. Hazar F1) were constituted and the yield and quality parameters found from these treatments were evaluated. The layout of the experiment was a completely randomized block design with three replications for each of the fourteen irrigation treatments tested. According to the content of the treatments, the irrigation amount water applied to the plants varied between 0 and 554 mm in the first year, and between 0 and 556 mm in the second year. Water consumption of tomato in the first year ranged between 300 and 725 mm and in the second year ranged between 340 and 746 mm. Yield, fruit weight, diameter, height and dry matter ratio were determined statistically significant. In 2009 and 2010 years, the maximum yield were found as 92.2 t ha(-1) and 93.4 t ha(-1) in V100F100Y100R100 treatments, while the minimum yield were found as 2.0 t ha(-1) and 4.0 ha(-1) in the V0F0Y0R0 treatments, respectively. Water- yield relationship factors (k(y)) in 2009 and 2010 years were found as 1.05 and 1.06, respectively. The maximum WUE and IWUE values were obtained from vegetative and ripening periods. Vegetative and ripening periods may be suggested as the maximum efficient irrigation periods for the tomato applied with drip irrigation under unheated greenhouse conditions.