The salt tolerance of four accessions of Arabidopsis thaliana (COL (Columbia), NOK2, N1438 and N1380) was evaluated during germination by the capacity of seeds to germinate in the presence of 50 mM NaCl and to maintain adequate acid phosphatase activity. Our results show that saline conditions reduced the final germination percentage, speed of germination and delayed the germination processes of accessions NOK2, N1438 and N1380. In contrast, 100% of germination was found in COL under salt-stress conditions. In the presence of NaCl 50 mM, acid phosphatase activity increased in the first 24 h, the activity reaching the control level in germinating seeds of COL, but in the three other accessions NOK2, N1438 and N1380, acid phosphatase activity diminished under salt stress. These findings suggest that changes in the phosphatase enzymes might play an important role in the acclimation of COL seeds to the changing environmental conditions.