Effect of seed size ( small, medium and large) on germination and seedling growth of triticale (xTriticosecale Witm. cv. Presto) at the different osmotic potential of NaCl and PEG solutions were determined in the present study. Germination tests were conducted under five osmotic potential levels (-0.45, -0.77, -1.03, -1.44 MPa, and Control) of PEG 6000 and NaCl. Germination percentage (%) at 4 and 8(th) days and also seedling growth traits such as root and shoot length ( mm), dry root and shoot weight (mg), root : shoot length ( R: S) ratio, and relative water content of shoot (RWC, %) were investigated in this study. The results indicated that decreases in the osmotic potentials caused a reduction in germination percentage and seedling growth. It was seen that drought created by PEG 6000 had more negative effects on germination and seedling growth than that of NaCl. In consequence, the total germinability and seedling growth were higher in large seeds rather than in small seeds in control solution and under osmotic stress. In addition, it was observed that seedlings obtained from larger seeds survived even at the lower osmotic potential of PEG and NaCl; whereas, seedling obtained from small seeds did not survive in the intensive stress.