Sarin gas was dispersed in a Tokyo subway in 1995. This study investigates the mental and somatic symptoms of the 34 victims 5 years after the attack. Structured interviews (Clinician-Administered Post-Traumatic Stress Disorder [CAPS] and Mini International Neuropsychiatric Interview) and self-rating questionnaires were used to assess the symptoms. Not only post-traumatic stress disorder (PTSD) but also non-specific mental symptoms persisted in the victims at a high rate. A total of 11 victims were diagnosed with current or lifetime PTSD according to CAPS. Victims with PTSD showed higher anxiety levels and more visual memory impairment. A significant correlation between the total score of Impact of Event Scale-Revised (IES-R) and CAPS was found, indicating that IES-R is a useful tool for evaluating PTSD.