AbstractWood-plastic composites (WPCs) are currently discarded using incineration treatment, which is very expensive. Hence, this study was performed to improve the biodegradation of WPCs, such that they could potentially be buried after use, and to estimate their bending strength. A biodegradation test (determining the ultimate aerobic biodegradability of plastic materials under controlled composting conditions) was performed according to ISO 14855-1. Two groups of specimens were prepared using rice-bran mixture as the bioresource. One group contained rice-bran mixtures of 5, 7.5, and 10 wt.% instead of wood flour contents, and another group contained rice-bran mixtures of 8, 16, and 24 wt.% instead of the talc component. During the 20 days of the biodegradation experiment, the WPC (control) showed 18% biodegradation, and 7.5%-rice-bran-mixture-added specimen showed the highest biodegradation of 32%. Furthermore, the bending strength (MOR) was increased by up to 140% by adding rice-bran mixture as a biodegradable component. Therefore, the rice-bran mixture improved the biodegradation and mechanical properties of WPCs.