An association has been noted between the presence of alexithymic characteristics and psychosomatic/stress-related illness. A hypothesis is presented here outlining the mechanisms through which stress and alexithymic characteristics contribute to the development of stress-related illness. This hypothesis, the stress-alexithymia hypothesis, is considered here in the context of stress research from both theoretical and empirical perspectives. From these considerations, it appears that the stress-alexithymia hypothesis does have a theoretical basis. Additionally, there is indirect empirical evidence supporting the proposed influence of alexithymic characteristics on the physiological stress response. It is suggested that future research should directly examine the influence of alexithymic characteristics on stress responding and use alexithymic characteristics heuristically to explore the role of affect in the illness process.