We review the empirical literature and critique four possible pathways linking alexithymia and physical illness; (a) alexithymia leads to organic disease through physiological or behavioral mechanisms: (b) alexithymia leads to illness behavior (physical symptoms, disability, excessive health care use) through cognitive or social mechanisms: (c) physical illness leads to alexithymia; and (d) both alexithymia and physical illness result from sociocultural or biological factors. Our review suggests that alexithymia is associated with tonic physiological hyperarousal, certain types of unhealthy behavior, and a biased perception and reporting of somatic sensations and symptoms. Alexithymia also appears to influence health care use, but in a complex fashion. Although trauma may give rise to alexithymia, whether physical illness such as chronic pain does so is not known, and there is little evidence that sociocultural or biological factors lead to both alexithymia and physical illness. We conclude that alexithymia probably influences illness behavior, but there is little support for the hypothesis that alexithymia leads to chronic organic disease, especially when one distinguishes organic disease from illness behavior.