study was carried out in 2012 to determine the effects of different irrigation intervals and irrigation water amounts on the cut flower performance of oriental lilium (Lilium L.) 'Casa Blanca' cultivated in greenhouse conditions. Different ratios of the plant water consumption (T-r) calculated using exterior radiation values of the greenhouse were applied to the plants as irrigation water. Irrigation water amounts varied between 199.3-589.0 mm, whereas measured plant water consumption (ETa) varied between 314.9-613.8 mm according to the treatments. Different irrigation water amounts and irrigation intervals had statistically significant effects on flower stem length, flower stem diameter, stem weight and number of flowers. In the study the stem length varied between 26.4-74.7 cm, stem weight varied between 72-175 g, stem diameter varied between 5.0-9.5 mm and the number of flowers buds varied between 3.6 and 8.0. The experimental treatment on which about 1.25 times of the potential plant water consumption calculated in two day intervals and the experimental treatment on which about 1.50 times of the potential plant water consumption calculated in four day intervals were selected as irrigation program.