The Minnesota Multiphasic Personality Inventory (MMPl) was used 10 assess personality changes in Vietnam combat veterans with Post·Traumatic Stress Disorder (PTSD). After either traditional medical treatment (TC) or alpha-theta brainwave neurofeedback therapy (BWT). Application of brainwave training for thirty 30·minute sessions resulted in decreases in MMPI T-scores on clinical scales labelled hypochondriasis, depression, hysteria, psychopathic deviate, masculinity-femininity, paranoia. psychasthenia, schizophrenia, hypomania, and social introversion-extroversion. The traditional medical control group showed decreases in T-scores only on the scah labeled schIzophrenia. All fourteen BWT patients initially, receiving psychotropic medication reduced their dosages after treatment, but only one of thirteen TC patients reduced dosage. A thirty-month follow-up study showed that all fourteen TC patients had relapsed. In contrast only three of fifteen BWT patients. These findings indicate that application of alpha-theta brainwave training is a more efficacious treatment modality in the treatment of PTSD and prevention of relapse.