The number of articles on alexithymia has been steadily increasing since the word “alexithymia” was coined in the 1970s to denote a common characteristic that is observed among classic psychosomatic patients in whom therapy was unsuccessful. Alexithymia, a disorder of affect regulation, has been suggested to be broadly associated with various mental and physical health problems. However, most available evidence is based on anecdotal reports or cross-sectional observations. To clarify the predictive value of alexithymia for health problems, a systematic review of prospective studies was conducted. A search of the PubMed database identified 1,507 articles on “alexithymia” that were published by July 31, 2011. Among them, only 7 studies examined the developmental risks of alexithymia for health problems among nonclinical populations and 38 studies examined the prognostic value of alexithymia among clinical populations. Approximately half of the studies reported statistically significant adverse effects, while 5 studies demonstrated favorable effects of alexithymia on health outcomes; four of them were associated with surgical interventions and two involved cancer patients. The studies that showed insignificant results tended to have a small sample size. In conclusion, epidemiological evidence regarding alexithymia as a prognostic risk factor for health problems remains un-established. Even though alexithymia is considered to be an unfavorable characteristic for disease control and health promotion overall, some beneficial aspects are suggested. More prospective studies with sufficient sample sizes and follow-up period, especially those involving life course analyses, are needed to confirm the contribution of alexithymia to health problems.