Levels of serum interleukin-1 beta (IL-1 beta) and soluble interleukin-2 receptor (sIL-2R) were assessed in 19 male patients with combat-related posttraumatic stress disorder (PTSD) in comparison to 19 age- and sex-matched healthy volunteers. Serum IL-1 beta levels (but not sIL-2R) were significantly higher (p < .001) in the PTSD patients than in the controls. IL-1 beta levels did not correlate with cortisol levels, severity of PTSD, anxiety, depressive symptoms, or alexithymia score; however, they did correlate significantly (r = .54, p < .005) with the duration of PTSD symptoms. It is possible that desensitization of the hypothalamic-pituitary-adrenal axis in chronic PTSD patients counteracts the stimulatory effect of IL-1 beta on cortisol secretion.