Objectives: To evaluate the use of intraoperative guidance by means of C-arm cone-beam computed tomography (CT) (cone-beam computed tomography [CBCT]) and the use of postoperative CBCT to assess for successful aneurysm exclusion in fenestrated branched endovascular aneurysm repair (FEVAR). Methods: Patients with FEVAR who underwent CBCT were retrospectively evaluated and categorized into one of two groups. The CBCT-fusion group was comprised of patients who underwent preprocedural CBCT to guide FEVAR using fusion imaging with multidetector computed tomography (MDCT). The postprocedure CBCT group consisted of patients undergoing CBCT following deployment of the endograft. Outcomes from the CBCT-fusion group were compared with historical controls. These controls were patients who underwent FEVAR for similar groups of abdominal and thoracoabdominal aortic aneurysms in the 12 months preceding the initiation of a CBCT program. The findings on postprocedural CBCT were compared with those on predischarge MDCT. Results are expressed as mean ±standard error of the mean, or as median and interquartile range. Results: Forty patients were included in the "CBCT-fusion" group and compared with the historical cohort. The use of perioperative guidance of FEVAR by means of CBCT resulted in a significantly lower contrast dose (94 cc [72-131] vs 136 cc [96-199]; P = .001). While there was a trend toward lower operative (330 minutes [273-522] vs 387 minutes [290-477]; P = .651) and fluoroscopy times (81 min [54-118] vs 90 minutes (46-128), P = .932); this difference did not reach statistical significance. Nineteen patients were included in the "postprocedural CBCT" group and compared with predischarge MDCT. Postoperative CBCT identified eight endoleaks. Type I and III (n = 6) endoleaks were identified and treated during the primary procedure. When CBCT did not show an endoleak, this was confirmed by MDCT. The use of CBCT required significantly less contrast compared to MDCT (50 cc [set amount] vs 100 cc [80-125]; P < .0001). Mean skin dose was 0.27 (0.011) Gy for preoperative CBCT and 0.552 (0.036) Gy for postoperative CBCT. Conclusions: CBCT is a valuable addition to complicated aortic interventions such as FEVAR. Intraoperative use utilizing fusion imaging limits contrast dosage and postdeployment CBCT is of sufficient quality to evaluate successful aneurysm exclusion and for detection of early complications after FEVAR. With the information we are able to obtain from the CBCT at the completion of the FEVAR, we can intervene on problems earlier and potentially decrease the subsequent need for reintervention.