This paper explores the tradeoffs between domestic and productive uses of biomass energy sources in the Nile Basin of Ethiopia using a non-separable farm household model where labor and other input allocations to energy collection and farming are analyzed simultaneously. We estimate a system of five structural equations using three stages least squares and find that use of dung as a domestic fuel source has a negative impact on agricultural productivity while, use of fuelwood is associated with increased productivity. In particular, on-farm production of fuelwood appears to provide many benefits for crop productivity and labor savings, by making fuelwood collection easier and more convenient for households. The results show that households remain reliant on multiple sources of traditional biomass fuels and that these are largely complementary. At the same time, rural households have limited options to meet their domestic energy needs, and most lack access to modern fuels and technologies. The discussion suggests ways of making domestic energy collection more efficient through policy interventions aimed at the promotion of agroforestry and increasing access to new energy-efficient technologies.