This study was conducted to compare the effect of NaCl levels on germination and seedling growth, and ion accumulation in five bitter vetch lines. Germination percentage (%), mean germination time (MGT, day), emergence percentage (%), shoot and root length (mm), shoot and root fresh and dry weight (mg/plant) and the Na(+), K(+), Cl(-), and Na(+)/K(+) ratio for both root and shoot were determined at different NaCl salt concentrations (0, 5, 10, 15 and 20 dS m(-1)). Results of this research showed that NaCl adversely affected germination time and the emergence percentage as compared to final germination percentage in all the lines. Seedling characters decreased with increasing NaCl levels, but the decrease was more acute in the shoots than in the roots. Salinity stress induced a significant increase in shoot and root Na(+), Cl(-) and Na(+)/K(+) ratio. Results show that line 1 was relatively more tolerant than other lines and line 2 was more sensitive. Salinity affected seedling growth especially at 10 dS m(-1) and higher salinity levels.