Evaluated the potential effects of psychological distress on physical symptoms observed in 48 Persian Gulf War veterans (aged 21-56 yrs) using a neuropsychological evaluation that included personality assessment. Cluster analysis of the validity scales resulted in a solution with 2 viable subgroups. Members of cluster 1 had significantly higher scores on 5 MMPI-2 clinical scales, a measure of trait anxiety, and a number of subjective complaints, including lower scores on a task of attention. Neuropsychological functioning did not otherwise differ between the groups. Contributions of personality style in coping with physical and mental health stressors were indicated. Experience of distress appeared to be attributable to individual differences rather than factors that have been associated with the elusive Gulf War syndrome. It is suggested that Persian Gulf War veterans' emotional reactions to clinical laboratory findings, perceptions of exposure risks, war experience, and stress may represent a variation of posttraumatic stress disorder (PTSD).