Brunei Darussalam is located near the equator in the Borneo Island. Abundant rain, humidity and sunshine have created one of the largest rain forests in the world. Seven samples of sawdust taken from this rainforest and were analyzed for their fuel value and environmental impact. Among the seven variety of variety of wood investigated, one was soft, two were light, and four were of the hard type. Properties, such as wood density, ash content and elemental composition of plants were assessed and correlated with the calorific value. This was evaluated in relation to their properties and environmental impact when burned. It was revealed that the sawdust with the highest calorific value does not necessarily constitute the best option as fuel, if elemental composition is taken into account. The variation in wood density, calorific value, ash content and elemental composition of C, N and S along with their indirect impact on the environment are discussed in this paper.