Estimation of biomass energy potential including biomass residue and forestry biomass in Thailand was carried out taking into account the amount of biomass residue which has already been used and the possibility of biomass energy plantation in accordance with the National Plan of the Thai Government. According to this estimation, 65 PJ can be derived from agricultural and forestry waste and 770 PJ can be generated if half of the area allocated for cultivation of plantation forests could be used for biomass energy plantations. Today, biomass energy is 810 PJ, which is 30% of the total primary energy. (C) 2000 Elsevier Science Ltd. All rights reserved.