Cholesterol and uric acid, which might correlate with steroidogenesis and monoamine functions, may change under emotionally stressful conditions and in mental disturbances. Among anxiety disorders, an increase of serum cholesterol has been observed in panic disorder. However, the issue has not been adequately investigated in other anxiety disorders, including post-traumatic stress disorder (PTSD). The present study investigated serum cholesterols, uric acid and cholinesterase in victims of the Tokyo subway sarin poisoning, 1995, in a series of 5-year follow-ups. Cholinesterase was studied, in relevance with serum lipid changes and symptoms of PTSD, and also in light of a biological effect of sarin. Out of 34 victims, eight developed PTSD and two were currently diagnosed with PTSD using the Clinician-Administered PTSD Scale (CAPS). No significant relationship was observed between PTSD and serum cholesterols or uric acid. Several factors including co-occurrence of other mental disturbances with PTSD, in addition to the limited sample size, might have affected the result. In contrast, serum cholinesterase level was significantly reduced in the victims with the development of PTSD, compared with the matched controls (P<0.02, t-test). This might partly reflect a long-term remnant effect of sarin intoxication, although an effect of the psychological experience could not be totally excluded.