Poly(lactic acid)/sugarcane bagasse fiber (PLA/SCBF) composites were prepared using melt compounding followed by compression molding. Epoxidized soybean oil (ESO) was selected as plasticizer for the PLA/SCBF composites. SCBF was alkali-treated and ground into powder form with the size of approximately 100 μm (hereafter designated as SCBFP). The properties of the PLA composites were assessed using impact tests, field-emission scanning electron microscopy, and dynamic mechanical analysis (DMA). DMA results showed that the addition of SCBF increased the storage modulus of PLA and the effect is more pronounced for the one containing SCBFP. The impact strength of PLA/SCBF composites was improved significantly by the addition of ESO.