Seed dormancy is a marked characteristic of forage grasses seeds and the understanding of the mechanisms of this phenomenon is of great importance concerning seed technology aspects. It is known that seed dormancy is naturally released as the time passes. The objective of this study was to investigate the release of Brachiaria brizantha seeds dormancy packed in two types of packages with different initial seed moisture contents and stored in a open warehouse in Campinas - SP, for 10 months. So that a seed lot harvested by ?ground sweeping? after cleaned and scarified with sulfuric acid and non scarified in commercial scale, were stored in multi wall kraft paper bags and polyethylene bags (194µm wall), with 6-7%, 10-11% and 13-14% seed moisture content and tested for germination on the beginning of the study and every two months. The remaining seeds of the germination tests were tested for viability through the tetrazolium test. The experimental design was completely randomized factorial (3x2x2x6). The results showed that: seed dormancy was not affected by the treatments; no more seed dormancy was observed in any treatment after fourth months of seed storage.