This study aimed at assessing outcomes after carotid endarterectomy (CEA) in dependence of center policy with respect to imaging intraoperative completion study (ICSi) usage. Although randomized controlled studies are missing, a beneficial effect was shown for ICSi techniques (i.e., angiography and intraoperative duplex ultrasound) after CEA. This secondary data analysis is based on the German statutory quality assurance database. Research was funded by Germany's Federal Joint Committee Innovation Fund (G-BA Innovationsfonds, 01VSF19016 ISAR-IQ). According to their ICSi policy, hospitals were categorized as routine ICSi (>90%), selective ICSi (10-90%), or sporadic ICSi (<10%) centers. Primary study outcome was in-hospital stroke or death. Multivariable regression analyses were performed. Between 2012 and 2016, a total of 119,800 patients underwent CEA. In-hospital stroke or death rates were lower in routine ICSicenters (1.7%) compared to selective (2.1%) and sporadic ICSicenters (2.0%). The multivariable regression analysis showed, that in routine ICSicenters, ICSi use was associated with lower rates of stroke or death (aOR 0.64; 95% CI 0.44-0.93). In selective ICSicenters, ICSi was not associated with the occurrence of either of the assessed outcomes. In sporadic ICSicenters, ICSi was associated with higher rates of stroke or death (aOR 1.91; 95% CI 1.26-2.91). Lowest in-hospital stroke or death rates are achieved in routine ICSicenters. While ICSi is associated with a lower perioperative risk in routine ICSicenters, it might act as a surrogate marker for worse outcomes due to intraoperative irregularities in sporadic ICSicenters. Routine use of ICSi is advisable.