Durian peel (DP) and spent mushroom compost (SMC) are considered as agricultural wastes. These two materials have potential for the briquetting process according to their quantities. In this study, cold densification method and extrusion process are adopted for solid bio-fuel briquettes. DP and SMC were pyrolysed, milled and combined together by adding 10% of cassava starch as a binder. The study has varied the mass ratio of DP and SMC chars at 10:0, 8:2, 6:4, 4:6, 2:8 and 0:10 respectively. Physical properties of the briquettes were investigated for heating value, ash and moisture content. The results show the highest heating value of 5,880 cal/g and 5,303 cal/g for the briquette made with DP and the mixture of DP and SMC at a mass ratio of 8:2 (Mix 4), respectively. The lowest ash content of 7.9% and 12.4% for the briquette made with DP and Mix 4, respectively. A heating value higher than 5,000 cal/g is acceptable in the market according to the Thailand community standard. DP and Mix 4 briquette had a good propertied as fuel and suitable as an environmentally friendly alternative energy source. Moreover, a payback period of DP and Mix 4 briquette less than three years can be achieved.