This study examined one group of veterans with post-traumatic stress disorder (PTSD) over the course of a four month inpatient treatment program. The aim of the study was to examine treatment process factors that may contribute to the generally poor outcome reported in previous studies. Group members made weekly ratings in the domains of PTSD symptoms, morale, interpersonal relationships, and physical problems. Results contrasted with clinical assumptions usually made regarding the treatment process in these programs. Despite an appearance of cohesion among group members, variation of scores on functional domains was explained largely by individual differences. Progress through the program showed a strongly linear pattern, with no phase effects. Somatic complaints did not increase during the phase when traumatic material was explored. Degree of improvement or worsening was best predicted by level of PTSD symptoms at admission, indicating that more symptomatic veterans did worse in the program. Additional factors of race, combat exposure, childhood abuse, and application for disability had no effect on the process variables measured.