Prior integration of any tree/shrub species in a given land use system there is always the need of undertaking a field trials for the adaptability and growth performance evaluation for particular environment. Study was designed and conducted to evaluate the adaptability potential and growth performance of six nitrogen fixing tree/shrub species in Dello-menna district of Bale zone, southeast Ethiopia. The considered species in the study are Cajanus cajan, Flemingya macrophylla, Gliricidia sepium, Sesbania sesban, Calliandra calothyrsus and Leucaena leucocephela. Seedlings were produced in a nursery site and transplanted to the experimental site. The experiment was laid out in RCBD design with three replications, and the management practices employed uniformly for each species throughout the stud period. In the study the necessary growth performance data parameters; plant height, root collar diameter and survival rate were measured and recorded. Thereafter, the data was analyzed by GenStat (15<sup>th</sup> ed) and Excel computerized programs. Results obtained showed that, these growth performance data parameters were significantly (p < 0.05) varied among the tested species. In this respect, Flemingya macrophylla, Sesbania sesban, Gliricidia sepium and Cajanus cajan attain the higher mean values in survival rate, plant height and root collar diameter. While Leucaena leucocephela and Calliandra calothyrsus attain the lowest mean values for the entire growth performance parameters. Hence, it can be inferred that the study site matched well with the environmental requirement of F. macrophylla, S. sesban, G. sepium and C. cajan. The species therefore offers much promise for future use in any of agroforestry practices in the area. However, evaluation of their contribution to soil fertility improvement and crop yield needs to be further investigated as this may insights to know their nutrient provision potential while integrated together with annual and/or perennial plants in agroforestry land use system.