Abstract Intercropping is an environmentally sustainable multiple cropping system widely practiced in small-scale farming communities in developing countries. Despite its high yielding potential, modern agriculture exploits the scarce agricultural land resources and contributes to the loss of biodiversity whilst intercropping diversifies species, increases and stabilises yield, and ensures food security. Maize-legume intercropping is a dominant cropping system in Ethiopia particularly in the lowlands but not common in the highlands where monocropping of small cereals is a traditional practice. It not only has the potential to break the disease cycle but can also be an additional source of income and food. This study was designed to evaluate the effects of proportion and arrangement of maize and faba bean intercrops on land use, cumulative yield and economic return. Here we show that intercropping increases cumulative productivity and profitability over years and ensures sustainability. Maize yield increased by 59% and 84% in the second and third years, respectively, while yield of faba bean declined by 67% in the second and third years. Sole maize had lower and sole faba bean had higher than their intercropping yields. The highest total LER of 2.11 was obtained from 100% maize: 75% faba bean combination which was equivalent to an additional 1.11 ha of land allocated to sole cropping. Overall, we recommend 100% maize: 25% faba bean for resource-limited farmers and 75% maize: 100% faba bean for commercial farmers based on the monetary advantage index. Moreover, 100% maize: 75% faba bean with acceptable monetary advantage was recommended for the commercial farmers.