Silicon carbide (SiC) composites reinforced with 10-50 mass% (10.5-51.2 vol%) of short Tyranno (R) Si-Zr-C-O fibre (average length similar to0.5 mm) and 0-10 mol% of Al4C3 as a sintering aid were fabricated using the hot-pressing technique. Firstly, the effect of Si-Zr-C-O fibre addition on the relative density (bulk density/true density) of the SiC composite hot-pressed at 1800 degreesC for 30 min was examined by fixing the amount of Al4C3 to be 5 mol%. Although the relative density was reduced to 87.4% for 10 mass% of Si-Zr-C-O addition, further increases in the amount of Si-Zr-C-O fibre increased density to a maximum of 92.8% at 40 mass% of fibre addition. Secondly, the effect of varying the amount of Al4C3 addition on the relative density was examined by fixing the amount of Si-Zr-C-O fibre to be 40 mass%. The optimum amount of Al4C3 addition for the fabrication of dense SiC composite was found to be 5 mol%. The fracture toughness of the hot-pressed SiC composites with 20-40 mass% of Si-Zr-C-O fibre addition (amount of Al4C3: 5 mol%) was 3.2-3.4 MPa . m(1/2) and approximately 1.5 times higher than that (2.39 MPa . m(1/2)) of the hot-pressed SiC composite with no Si-Zr-C-O fibre addition. SEM observation showed evidence of Si-Zr-C-O fibre debonding and pull-out at the fracture surfaces. The hot-pressed SiC composite with 5 mol% of Al4C3 and 40 mass% of Si-Zr-C-O fibre additions showed excellent heat-resistance at 1300 degreesC in air due to the formation of a SiO2 layer at and near exposed surfaces.