After rubber tree (Hevea brasiliensis Muell. Ag.) seeds reach the physiological maturity, there is a relatively dry and cold period in the State of Sao paulo, which led to the present work, in order to evaluate environmental conditions that maintain physiological seed quality. The physiological quality of rubber tree seeds, treated with benomyl (0.1;) and stored in plastic bags, was studied up to 5 months, during 87/88. The seed bags were kept under laboratory conditions during the whole storage period. To evaluate physiological seed quality, germination and vigor (germination speed and seedling length) tests were performed. Germination and germination speed were measured at 30 C, as well as under environmental conditions. There was no treatment effect on the maintenance of seed quality during storage. The germination, germination speed and seedling length were reduced as the storage period increased. The germination values were low since the bigining, which could be attributed to the low moisture content (25,4;) of the seeds. The germination test for rubber tree seeds can be performed using sand as substrate at 30 C and the final count made at the 20th day after planting.