The on-farm storage structures in Nigeria which are managed by individual farm-families, account for about 85% of the food storage volume. The food security for Nigerians depends critically on the inventory management of the on-farm storage varieties. The economic viability of rhumbu (local granary), the most popular storage structure among the rural residents are, therefore, appraised in this paper. Applying measures of project worth on data from 1582 farm-families drawn by ballot from all the ecological zones in Nigeria, the rhumbu storage project is found to be economically viable. The net present value (NPV), benefit-cost ratio (BC) and internal rate of return (IRR) are N5.87 million, 1.97 and 96.78%, respectively. Allowing 35% storage losses, the rhumbu storage project is still economically viable since the computed IRR is reduced by about 52.33%. But an increase by 100% in the initial cost outlay still leaves the storage project viable economically. Farm-families are therefore likely to accommodate the additional cost which the improved rhumbu technology may involve. There is, therefore, a strong need for the dissemination of strong, airtight fumigation and modified atmosphere rhumbu technology packages among the rural Nigerian farmers.