Livestock production in the lowlands of Eastern Oromia of Ethiopia depends mainly on natural pastures and crop residues which are of poor quality and the yield is generally low during the dry season. Therefore, there is a need to introduce alternative forages of high quality that are adapted to the region. The objective of this study was to identify and select the best Brachiaria grass accession/s for dry matter (DM) yield and nutritive quality in lowlands of Eastern Oromia. The experiment was conducted in the lowlands of Fedis and Dire-Dawa districts during 2018 to 2020. The experimental materials were brachiaria decumbens accessions 1087, 13205, 14721, 14720 and brachiaria ruziziensis accessions 13332, 14743, 14771, 14774, 14813. These grass accessions were compared with one local check, a locally cultivated brachiaria grass. Plant established successfully at both sites for the last three years. Tiller numbers, plant height, forage dry matter yield and plot covers were recorded at 16 weeks after planting. Significant (p<0.05) difference were detected among the tested grass accessions in plot cover, height, tiller number, dry matter yield, OM%, Ash%, CP%, NDF%, ADF% and ADL% contents. The results showed that brachiaria grasses had the potential to provide forage of high quality and adequate quantity for livestock feed. Accession of brachiaria ruziziensis 14813 (24.685 t/ha) and brachiaria decumbens 14721 (20.89t/ha) showed the highest forage dry matter production than the remaining evaluated grass accessions. Although brachiaria grass accession 14720 and 13205 had higher CP content than accessions 14721, high forage dry matter yield is more appealing to farmers it is not recommended for cultivation in the study area. Thus, these two grass accessions brachiaria ruziziensis 14813 and brachiaria decumbens 14721 are the most suitable for providing better quality and quantity of livestock feed in the lowlands of Eastern Oromia, Ethiopia and similar agro-ecologies to the study area.