This paper is concerned with fatigue studies on polypropylene/glass-fibre thermoplastic composites produced from a bidirectional woven cloth of commingled E-glass and polypropylene fibres (the latter becoming the matrix after the application of heat and pressure). This composite was manufactured with a fibre volume fraction of 0.338. The effects of frequency, stress ratio, temperature and stress concentration on the fatigue performance were considered. The stress concentration was induced by circular holes in specimens loaded in tension. Stress/life fatigue curves, the rise in temperature of the specimens during the tests and the loss of stiffness were obtained and are discussed.