In this study, the effect of oligomeric siloxane on the mechanical properties of jute fabric-reinforced low-density polyethylene (LDPE) composites is examined. After alkali treatment of jute fabric, oligomeric siloxane treatment is conducted to promote adhesion between jute fiber and polyethylene matrix. Mechanical properties of fabricated composites such as tensile strength, flexural strength, and interlaminar shear strength (ILSS) were evaluated. The tensile strength is observed to increase from 17.5MPa for untreated jute fabric/LDPE composite to 27.7MPa for oligomeric siloxane-treated alkalized jute fabric/LDPE composite. Provided that jute fabric is treated with alkali and oligomeric siloxane, a 39% increase is observed in the flexural strength. It is interesting to note that the effect of siloxane treatment after alkalization procedure of jute fabric on ILSS of jute/LDPE composite is due to the fact that 98% improvement is obtained. It can be observed that the adhesion between jute fiber and LDPE also improves to a great extent through both alkali and oligomeric siloxane treatment, respectively. These results are also confirmed by the SEM observations of fracture surfaces of jute/LDPE composites.