Natural fiber Kenaf (Hibiscus Cannabinus) as a filler (filler) has been developed as an ingredient for applications in the automotive field, especially in the manufacture of interior panels in cars. The advantages of kenaf fibers are of low economic value and have relatively higher mechanical strength than other natural fibers such as sisal, cotton, abaca, hemp and coconut fibers. However, natural fiber composites have lower mechanical properties compared to composite reinforced synthetic fibers. Therefore, it is necessary to add other fillers to improve the mechanical properties. One of them is the addition of microsilica particles, known as silica-fume. This study aims to study the effect of variations in fiber length on the mechanical properties and absorption of kenaf / epoxy composite with and without the addition of silica-fume. The fiber used was alkali-treated kenaf fiber in 6% NaOH solution for 36 hours at room temperature. Kenaf fibers were then chopped in 4 mm, 6 mm, 10 mm length. The ratio of fillers (kenaf and silica-fume) to the matrix is 30 (27 (kenaf) : 3 (Silica-fume)) : 70. The hybrid composites of kenaf/silica-fume/epoxy were fabricated by one layer random fiber method using a hot press molding machine at bending dan water absorption 1700 Psi and impak 1160 Psi, 100°C for 25 min. The mechanical tests performed are bending and impact tests, which refer to ASTM D 790 and ASTM D 6110-04, respectively. Physical tests of water absorption and thickness swelling were carried out refer to ASTM D 750-98 for 216 hours of immersion time. Impact fracture surfaces were characterized using scanning electron microscopy (SEM). The results indicated that the addition of silica-fume improved the bending properties of kenaf/silica-fume/epoxy, but not for the impact properties. The highest value of those mechanical properties was shown in the composite with and without the addition of silica-fume at 4 mm fiber length. The maximum bending strength and modulus were 54.820 MPa and 3.862 GPa, respectively, for the composites with adding silica-fume. The highest impact strength 8.129 Kj/m², however, was shown in the composite without silica-fume. The lowest water absorption (11.5%) and thickness swelling (9.05%) were obtained from the composites with the addition of silica-fume at the fiber length 4 mm after 216 h.