Ninety-eight victims of recent motor vehicle accidents (MVA), who sought medical attention as a result of the MVA, were followed up prospectively 6 months after the initial assessment, using Keller, Lavori, Friedman, Nielsen, Endicott, McDonald-Scott and Andreasen's (Archives of General Psychiatry, 44, 540-548, 1987) LIFE methodology so that month-by-month changes in post-traumatic stress disorder (PTSD) symptoms could be determined. For the 40 MVA victims who initially met the full criteria for PTSD, 10 no longer met the criteria 4 months after the initial assessment, a decrease significant at the P < 0.01 level, and 20 no longer met the full criteria at 6 months (P < 0.001). On a symptom-by-symptom basis, there were significant declines among the fraction of those who initially met the criteria for PTSD for all avoidance and numbing symptoms by the 6-month follow-up, whereas most of the hyperarousal symptoms did not show significant declines.