This paper investigates the effect of finite specimen size upon the tensile failure of a tridirectional carbon-carbon composite along each reinforcement axis. Asymmetry in the position of load-bearing axial yarns across the cross-section is generated randomly by machining. This yields parasitic bending of the specimen, and thereby premature failure of the yarns subjected to the maximum bending stress. However, bending effects become negligible at final failure. Additionally, the composite failure strength sigma(F) is determined from the cross-sectional area of the actually load-bearing axial yarns, using both symmetrical and asymmetrical specimens. Results are in good agreement with previous work, and we show that the variability of sF is small. (C) 2003 Kluwer Academic Publishers.