A self-rating scale, the Subjective Symptom Checklist (SSC) was developed to assess PTSD patients perception of their symptoms between treatment sessions. Reliability and validity of the scale were acceptable. The scale was used in a treatment trial comparing the efficacy of cognitive therapy versus imaginal exposure. Conventional pre-post treatment comparisons using standardized assessments showed no differences between the two treatments. However, when patients who failed to respond to treatment were excluded, group treatment effects became apparent. Patients who received imaginal exposure showed a significantly greater reduction in subjective ratings of their symptoms than did those who received cognitive therapy. It was cautiously concluded that although some PTSD patients could not tolerate exposure, those who could may receive greater subjective benefit than those who received cognitive therapy.