Numerous studies have found that patients diagnosed with TIA have decreased health-related quality of life, which has been interpreted as suggesting that patients with TIA have residual symptoms after the event. Studies assessing health status in the same patients before and after an event are lacking but may allow a direct determination of the association of TIA with postevent health status. To examine patient-reported health before transient ischemic attack (TIA) among individuals diagnosed with this event and evaluate change in patient-reported health after the event overall and by TIA characterization subgroups. This cohort study was conducted among 236 patients with a clinical diagnosis of TIA from October 2015 to December 2017 in a large US health system that collects a patient-reported outcome measure in ambulatory setting as part of routine care. Included patients had patient-reported global health scale assessments completed as part of routine care before and after a TIA event. Data were analyzed from March through July 2020. The main outcome was Patient-Reported Outcome Measurement Information System Global Health (PROMIS GH) scale score before and after TIA. A change of 5 or more points in this score is considered clinically relevant. The secondary outcomes included change in patient-reported global health by clinical impression of the probability of a TIA event, pattern of neurological deficits, and short-term risk of stroke, as assessed by the ABCD2 score. Among 263 patients who experienced TIA, mean (SD) age was 67.9 (13.4) years and 138 (52.5%) were women. The median (interquartile range) time between patient-reported global health scores was 152 (94-284) days. Mean (SD) baseline patient-reported global physical health and mental health scale summary scores were 43.4 (8.2) and 47.7 (9.7), respectively, and were statistically significantly decreased compared with the general population mean (SD) scores of 50 (10; P < .001) for physical and mental health. The difference between physical health summary score among study participants and the general population was clinically relevant. Mean (SD) summary scores were not statistically significantly different after the event compared with before the event overall (physical health: 44.1 [8.2], for a mean [SE] improvement of 0.65 [0.38] points; P = .09; mental health: 47.4 [9.1], for a mean [SE] worsening of 0.25 [0.38] points; P = .51) or within subgroups. These findings suggest that impaired health status among patients diagnosed with TIA reflect, at least in part, an impaired premorbid state of health. This study did not find that TIA events were associated with worsening of health status overall or within subgroups.