Indonesia is a developing country which economy relies heavily on agricultural production. From such activities a large amount of crop residues are produced each year which could be of potential for energy purposes. Unfortunately, there is an increasing concern over the open burning of biomass resources in the country and notably crop residues that are left unused in the field. Such practices lead to air pollution, human health and economic impacts. This study aimed at investigating farming practices in Indonesia for major crops and estimating the proportion of crop residues unused and subject to open burning that could potentially be available as energy feedstock. One specific location in Indonesia was selected as representative case-study and a field survey using questionnaires conducted. It was found that 21% of Indonesia's crop residues are subject to open burning. On an annual basis, this corresponds to about 45 million tonnes of residues, including, 19.3 million tonnes of rice straw, 18.5 million tonnes of cassava residues, 6.7 million tonnes of corn residues, and 0.4 million tonnes of sugarcane residues. The total energy potential such biomass could represent on a daily basis was estimated to amount to 1706 TJ.