In the present study, characterization and assessment of high abiotic stress tolerance of clusterbean rhizobia were investigated under in vitro, in vivo and axenic conditions. Total 85 clusterbean rhizobial isolates were retrieved from 43 different nodules collected from various locations of four districts under hyper-arid zone of Rajasthan, India. Most Probable Number (MPN) count of different districts soils revealed that soils of Barmer possess the highest rhizobial population with the lowest count in soils of Jaisalmer district. Strong positive correlation was also observed between the percent organic carbon of different soils and MPN counts of rhizobia of respective soils. Among all isolates, 29 isolates showed steady growth at high concentration (40%) of polyethylene glycol 6000 and high temperature of 45oC. Stress-tolerant rhizobial isolates also harbored multiple PGPR traits like nitrogen fixation, phosphate solubilization, IAA production and ACC deaminase activity. Four promising stress-tolerant rhizobial isolates along with one reference strain (GSS) were evaluated for nodulation efficiency and plant growth promotion in clusterbean under axenic condition using Leonard jar assemblies for high temperature tolerance and in pot-house condition for drought tolerance at different soil moisture regimes of 100%, 50% and 25% field capacity (FC). Leonard jar experiment revealed that rhizobial isolate ClBk43B possessed significantly better potential to enhance maximum biomass yield around 85.0% increase under high temperature and pot experiment showed that isolate ClBr87A inoculated plants acquired enhanced dry matter yield with 93.6% increase at 25% FC than non-rhizobial control. Hence, these two isolates ClBk43B and ClBr87A showed the tremendous potential as bioinoculant for arid zone of India.