Objective: Fenestrated-branched endovascular aneurysm repair (FBEVAR) has expanded the treatment of patients with thoracoabdominal aortic aneurysms (TAAAs). Previous studies have demonstrated that women are less likely to be treated with standard infrarenal endovascular aneurysm repair because of anatomic ineligibility and experience greater mortality after both infrarenal and thoracic aortic aneurysm repair. The purpose of the present study was to describe the sex-related outcomes after FBEVAR for treatment of TAAAs. Methods: The data from 886 patients with extent I to IV TAAAs (excluding pararenal or juxtarenal aneurysms), enrolled in eight prospective, physician-sponsored, investigational device exemption studies from 2013 to 2019, were analyzed. All data were collected prospectively, audited and adjudicated by clinical events committees and/or data safety monitoring boards, and subject to Food and Drug Administration oversight. All the patients had been treated with Cook-manufactured patient-specific FBEVAR devices or the Cook t-Branch off-the-shelf device (Cook Medical, Brisbane, Australia). Results: Of the 886 patients who underwent FBEVAR, 288 (33%) were women. The women had more extensive aneurysms and a greater prevalence of diabetes (33% vs 26%; P = .043) but a lower prevalence of coronary artery disease (33% vs 52%; P < .0001) and previous infrarenal endovascular aneurysm repair (7.6% vs 16%; P < .001). The women had required a longer operative time from incision to surgery end (5.0 ± 1.8 hours vs 4.6 ± 1.7 hours; P < .001), experienced lower technical success (93% vs 98%; P = .002), and were less likely to be discharged to home (72% vs 83%; P = .009). Despite the smaller access vessels, the women did not have an increased incidence of access site complications. Also, the 30-day outcomes were broadly similar between the sexes. At 1 year, no differences were found between the women and men in freedom from type I or III endoleak (91.4% vs 92.0%; P = .64), freedom from reintervention (81.7% vs 85.3%; P = .10), target vessel instability (87.5% vs 89.2%; P = .31), and survival (89.6% vs 91.7%; P = .26). The women had a greater incidence of postoperative sac expansion (12% vs 6.5%; P = .006). Multivariable modeling adjusted for age, aneurysm extent, aneurysm size, urgent procedure, and renal function showed that patient sex was not an independent predictor of survival (hazard ratio, 0.83; 95% confidence interval, 0.50-1.37; P = .46). Conclusions: Women undergoing FBEVAR demonstrated metrics of increased complexity and had a lower level of technical success, especially those with extensive aneurysms. Compared with the men, the women had similar 30-day mortality and 1-year outcomes, with the exception of an increased incidence of sac expansion. These data have demonstrated that FBEVAR is safe and effective for women and men but that further efforts to improve outcome parity are indicated.