This pilot study describes a prospective life-charting method for posttraumatic stress (PTS) symptoms. This method summarizes daily symptoms, functional impairment, life events, substance use, and treatment. Findings include experience with 17 cases over periods lasting from 3 to 25 months, with a description of 4 case examples that are characteristic of the pilot sample. People with posttraumatic stress disorder (PTSD) can complete day charting of their symptoms over an extended period of time. Some people reported that day charting distressed them mildly as they analyzed daily thoughts or feelings that they ordinarily avoided or pushed from awareness. Nonetheless, most people reported that they learned and benefited from daily symptom charting. In addition to enhancing patient self-understanding (or "insight"), the method may prove useful in assessing treatments for PTSD. Finally, these preliminary findings have suggested hypotheses regarding the clinical phenomenology and course of PTSD. For example, PTS symptom cluster exacerbation, severity, and duration appear to be highly consistent within any given patient, but highly variable across patients. Daily charting of PTS symptoms over prolonged periods is feasible. This prospective PTSD symptom charting method may have therapeutic, clinical, and research potential for understanding individual and group patterns in PTSD over time.