Chickpea is one of the cool seasons legume cultivated in many part of the world. Ethiopia is thernlargest chickpea growing country in Africa. The major producing areas are concentrated inrnAmhara and Oromia Regional States. In areas where there is depletion of soil with nitrogenrnfertilizer, must be inoculated with the most symbiotically effective isolates to restore thernfertility status of the soil. Therefore to develop inoculants, isolates must first be screened andrncharacterized to know their status. The failure of some rhizobial isolates to re-inoculate theirrnhost in the previous work by Daniel Muleta (2009) needed further search for screening ofrnisolates. So this study was aimed to characterize chickpea isolates from some major growingrnareas. Thirty eight chickpea root nodules were collected from farmers plots in South and NorthrnWollo zones. Ten of the isolates were rejected in the process of isolation and presumptive tests.rnThe rest were reinoculated in to their host for authentication. From the reinoculated isolates,rntwenty seven formed nodules in their host but one isolate failed to form nodule upon reinoculation.rnThe authenticated rhizobia were characterized based on their, morphological andrneco-physiological features. From the preliminary screening 96% of the isolates were fastrngrowing rhizobia. Symbiotic effectiveness of isolates showed significant difference in percentrneffectiveness (34-92%) on the host plant. AAUCR 27 and AAUCR 9 were found to be the mostrneffective isolates with percent effectiveness of 81% and 92% respectively. The majority ofrnisolates were categorized under effective rate which posses percent of effectiveness 50-80%.rnIsolates were also tested for their tolerance to different eco-physiological features such as pH,rntemperature, salt concentration, intrinsic antibiotic resistance and utilization of differentrnnitrogen sources. These tests showed the presence of wide physiological diversity betweenrnisolates. Plants inoculated with different isolates displayed differences in respect to nodulernnumber, nodule dry weight and shoot dry weight. The numerical analysis of isolates based onrnforty six phenotypic features showed the presence of diversity among isolates and alsornstatistical analysis indicates their diversity towards symbiotic effectiveness. Some isolates suchrnas AAUCR 9 and AAUCR 27 that are highly effective and tolerant to a wide range ofrnphenotypic features are promising in the development of inoculants.rnKey words/ phrases: Biological nitrogen fixation, Nitrogenase, Inoculants, Phenotypicrndiversity