The tensile fatigue behaviour of a tightly woven carbon/carbon composite was investigated as a function of stress level. Load-controlled fatigue tests were performed in tension-tension mode with a stress ratio, R, of 0.1 under ambient laboratory conditions. Results of composite behaviour are discussed in terms of the relationship of the stress/strain behaviour to the fatigue life of these composites as well as the effects of applied stress levels. It is shown that these composites exhibit good resistance to cyclic loading. No fatigue failures were obtained after 10(6) cycles when the maximum tensile load in the fatigue cycle is less than or equal to 80% of the static tensile strength. Evidence of textural changes related to fatigue was observed in the matrix region of these composites.