Wachabauer D, et al. - This study was intended to determine National Diagnostic Reference Levels (NDRLs) for CT for Austria on adult individuals. The datasets were requested from all Austrian hospitals and radiology centers with CT-scanners in the course of a nationwide survey on common CT-examinations between June 2018 and November 2018. All departments were invited to report a minimum sample of 10 representative dose length product (DLP) values per examination type and CT-scanner, including information about scan sequences, iterative reconstruction (IR) algorithms and, if available, patient data. The new proposals for CT NDRLs for Austria based on a nationwide survey are on average 13% lower than the current Austrian NDRLs and communicate well to current German and Swiss NDRLs. For DLP, 3rd quartiles are dependent on gender, the use of IR and the year of manufacture of the CT-scanners.