Developing countries suffer from both lack of resources and appropriate solid waste management systems. Therefore, the introduction of alternative options for waste valorisation is imperative. The current research introduces an environmental Life Cycle Assessment (LCA) of waste-based briquettes produced with 80 % of non-recyclable cardboard waste from separate collections and 20 % sawdust from sawmills in Bolivia. The aim is to compare the environmental impacts generated within the briquette's life cycle with conventional fuels. Primary data from a development project implemented in La Paz in 2021 were collected for building the inventory. SimaPro9.0 was employed to conduct the analysis, with IMPACT2002+ as the impact assessment method. Results' normalization, contribution evaluation, interval assessment, and sensitivity analysis were carried out, and the results were compared with conventional fossil fuels, namely: coal, methane, and LPG. Results suggest that briquettes' life cycle contributes to seven of fifteen impact indicators, with global warming, use of non-renewable energy, and respiratory inorganics, the most important. The global warming potential ranges from 23.9 to 26.7 gCO2-eq. MJ−1, lower than about 485 % compared to coal and 185 % to methane. Considering the avoided impacts from wood and methane substitution, global warming potential can decrease to about 20.0 and 18.9 gCO2-eq. MJ−1 respectively. On balance, compared to other fuels for heating and cooking, waste-based briquettes always have better environmental performance transporting the briquettes to about 100–130 km from the production plant. These results suggest that waste-based briquettes can contribute to mitigating environmental impacts and carbon footprint at a global level.