This article evaluates the potential impact of adopting improved legume technologies on rural household welfare measured by consumption expenditure in rural Ethiopia and Tanzania. The study utilizes cross-sectional farm household level data collected from a randomly selected sample of 1313 households (700 in Ethiopia and 613 in Tanzania). The causal impact of technology adoption is estimated by utilizing endogenous switching regression. This helps estimate the true welfare effect of technology adoption by controlling for the role of selection problem on production and adoption decisions. The analysis reveals that adoption of improved agricultural technologies has a significant positive impact on consumption expenditure (in per-adult equivalent terms) in rural Ethiopia and Tanzania. This confirms the potential role of technology adoption in improving rural household welfare as higher consumption expenditures from improved technologies translate into lower poverty, higher food security and greater ability to withstand risk. An analysis of the determinants of adoption highlighted inadequate local supply of seed, access to information and perception about the new cultivars as key constraints for technology adoption.