A study was conducted to examine the effects of different temperatures and water stress on Encholirium spectabile seeds. We evaluated the germination percentage, speed and time of germination of small (<2.97 mm), medium (2.97 ≤ M ≤ 4.01 mm) and large seeds (>4.01 mm), at temperatures of 15°C, 20°C, 25°C, 30°C, 35°C, 40°C and 45°C and a photoperiod of 12 hours of light. Seeds were subjected to osmotic potentials of 0, -0.2, -0.4, -0.6, -0.8, -1.0, -1.2 and -1.4 MPa, induced by solutions of polyethylene glycol. The results indicated an excellent germination of medium and large seeds at the temperatures of 20°C, 25°C, 30°C and 35°C. The temperature of 35°C provided the best mean germination time of large seeds and a higher speed rate of medium and large seeds. E. spectabile seeds germinate in a wide range of water deficit of -0.2 to -1.2 MPa. Germination reduced at concentrations of -1.0 and -1.2 MPa. No germination occurred at -1.4 MPa. Larger seeds showed the higher germination potential than medium and small seeds at the temperatures of 25°C, 30°C and 35°C and in the range ofwater deficit of -0.2 to -1.2 Mpa.