The development of natural fiber composite has been increasing annually in various aspects, for example, in the biomedical field. Natural fiber composite increasing because natural fibers are easily available at low cost, easy to process, low density, environmentally friendly, and can be decomposed biologically. The purpose of this study is to make hybrid low-density polyethylene (LDPE) composites with sisal fiber fillers and carbon fiber as an alternative material for biomedical devices and to know the mechanical properties of bending and physical properties of hybrid water absorption composite materials with variations in sisal and carbon. Fabrication of hybrid composites was carried out using the random fiber method using an engineered hot press, at a temperature of 115 oC with a pressure of 1.449 MPa for 15 minutes. Sisal fiber fillers were alkaline treated with 6% of NaOH for 36 at in, cut at 6 mm long. The treatment of carbon fiber was carried out by soaking liquid nitrogen for 10 minutes and cut at a length of 10 mm arranged manually using the hand lay-up method. The composition of the composites with matrix/filler ratio at 80/20 wt%, and the ratios of sisal and carbon fibers are 3:1, 2:1 and 1:1. Bending tests was conducted according to the ASTM D790-03 standard, and water absorption test was according to ASTM D570 is carried out on all hybrid composite specimens. Then the characterization of the bending test fault structure is carried out from the side of the cross section using an optical microscope. The results showed that the sisal/carbon/LDPE hybrid composites with the highest bending strenght and modulus of elasticity were found at the ratio of sisal/carbon 1:1 which was 26.32 MPa and 2.128 GPa, respectively and water absorption and thickness swelling tests of 4.8% and 3%, respectively these results can also be explained from composite cross-sectional photo macro resulting from bending tests that show better fiber matrix bonds than, that at the ratio of 3:1 and 2:1.