Ethiopia’s construction industry is aggressively expanding than ever before. Cement is the most essential and expensive material in this regard. Cement takes 10%–15% by volume of concrete. Nowadays, the construction industry is challenged by the scarcity of cement and price escalation of the cement market. However, scholars try to replace cement with pozzolanic material. Besides this, they investigated that bamboo leaf ash possesses pozzolanic properties. Ethiopia has about 850,000 hectares of lowland bamboo, so it is good to utilize bamboo leaf ash as a replacement material for cement. In this study, the capability of lowland Ethiopian bamboo leaf ash as a partial substitute for cement in C-25 concrete production with 0%, 5%, 10%, 15%, and 20% replacement of OPC by BLA with 0.49 percent water-to-cement ratio was investigated. This study examines the chemical properties of BLA, physical properties of cement paste, workability, compressive strength, water absorption, density, and sulfate attack of concrete. The chemical composition of bamboo leaf ash was examined, the summation of SiO2, AlO3, and FeO3 is 76.35%, and the ash was classified class N pozzolan. The normal consistency percentage of water increases as the BLA replacement amount increases, and both initial and final setting time ranges increase as the BLA replacement amount increases. The compressive strength of concrete for 5% and 10% BLA achieves the target mean strength (33.5 MPa) on the 28th day, and on the 56th day, 5% and 10% replacements increase the concrete strength by 1.84% and 0.12%, respectively. The water absorption and sulfate attack have significant improvement of the BLA-blended concrete on 5% and 10% BLA content. According to the findings, bamboo leaf ash potentially substitutes cement up to 10%. The outcome of the study will balance the cement price escalation and increase housing affordability without compromise in quality.