This study reports the results of a 5-year follow-up evaluation of 13 Vietnam combat veterans with chronic posttraumatic stress disorder (PTSD) who participated in a study of eye movement desensitization and reprocessing (EMDR) therapy previously reported in this journal. Pretreatment and follow-up psychometric outcome measures were compared with those of a demographically matched control group of 14 combat veterans with chronic PTSD who did not receive EMDR. Analysis of variance showed that the modest to moderate therapeutic benefits that were manifest immediately following EMDR were lost at the 5-year follow-up evaluation, and there was an overall worsening of PTSD symptomatology over the 5-year period in both EMDR-treated and nontreated control subjects. This is a US government work. There are no restrictions on its use.