The mechanical properties, thermal behaviors and morphology of poly(butylene succinate) (PBS)/microcrystalline cellulose (MCC) composites were investigated. The MCC used in this study was prepared by hydrolyzing cotton fabric waste with 2.5 N hydrochloric acid at 100°C for 30 min. PBS was melt mixed with three loading of MCC (10, 20 and 30 wt%) in an internal mixer, followed by compression molding into 0.3-mm sheet. The effects of MCC on the tensile properties, thermal stability, crystallization and morphology were investigated using the Instron testing machine, thermogravimetric analyzer, differential scanning calorimeter and scanning electron microscope, respectively. The incorporation of MCC into PBS results in a significant increase in the Young’s modulus but a decrease in the tensile strength and elongation at break. Moreover, the thermal degradation of the composites was not improved after introducing MCC into PBS. It was also found that, the MCC did not affect the melting temperature, but induced a slight increase in the crystallization temperature of the composites. The SEM micrographs show brittle fracture surfaces of the composites where the pull out MCC particles and pull out holes were observed.