This paper presents results from a comparative analysis of environmental income from approximately 8000 households in 24 developing countries collected by research partners in CIFOR's Poverty Environment Network (PEN). Environmental income accounts for 28% of total household income, 77% of which comes from natural forests. Environmental income shares are higher for low-income households, but differences across income quintiles are less pronounced than previously thought. The poor rely more heavily on subsistence products such as wood fuels and wild foods, and on products harvested from natural areas other than forests. In absolute terms, environmental income is approximately five times higher in the highest income quintile, compared to the two lowest quintiles. The study finds that environmental income plays a significant role in rural livelihoods, with forests contributing 22.2% of total household income. Non-forest environmental income adds another 6.4%, bringing the total environmental income contribution to 27.5%. Forests are the primary contributor to environmental income, but non-forest environmental income also plays an important role in rural livelihoods. The study also finds that environmental income is more important for low-income households, with the poorest households relying more on subsistence products. The study uses a standardized set of village and household-level questionnaires to elicit comprehensive data about the importance and role of environmental income in rural livelihoods. The data collection was done by 33 PhD students and junior scholars; the research design and methods were developed by an interdisciplinary team of scientists. The hallmarks of the data collection effort are detailed questions on all household income sources, using short (1–3 months) recall periods, and quarterly visits to households. The study addresses three broad questions: (1) how much does environmental income contribute to rural households' income portfolios in different study regions? (2) how does reliance on environmental income vary with different levels of income, including its influence on income inequality? (3) what household-level characteristics and contextual variables affect the magnitude and relative importance of environmental income? The findings have important implications for how we understand rural livelihoods and how we should design interventions that affect access to and use of natural resources.This paper presents results from a comparative analysis of environmental income from approximately 8000 households in 24 developing countries collected by research partners in CIFOR's Poverty Environment Network (PEN). Environmental income accounts for 28% of total household income, 77% of which comes from natural forests. Environmental income shares are higher for low-income households, but differences across income quintiles are less pronounced than previously thought. The poor rely more heavily on subsistence products such as wood fuels and wild foods, and on products harvested from natural areas other than forests. In absolute terms, environmental income is approximately five times higher in the highest income quintile, compared to the two lowest quintiles. The study finds that environmental income plays a significant role in rural livelihoods, with forests contributing 22.2% of total household income. Non-forest environmental income adds another 6.4%, bringing the total environmental income contribution to 27.5%. Forests are the primary contributor to environmental income, but non-forest environmental income also plays an important role in rural livelihoods. The study also finds that environmental income is more important for low-income households, with the poorest households relying more on subsistence products. The study uses a standardized set of village and household-level questionnaires to elicit comprehensive data about the importance and role of environmental income in rural livelihoods. The data collection was done by 33 PhD students and junior scholars; the research design and methods were developed by an interdisciplinary team of scientists. The hallmarks of the data collection effort are detailed questions on all household income sources, using short (1–3 months) recall periods, and quarterly visits to households. The study addresses three broad questions: (1) how much does environmental income contribute to rural households' income portfolios in different study regions? (2) how does reliance on environmental income vary with different levels of income, including its influence on income inequality? (3) what household-level characteristics and contextual variables affect the magnitude and relative importance of environmental income? The findings have important implications for how we understand rural livelihoods and how we should design interventions that affect access to and use of natural resources.