PURPOSE Analysis, evaluation and classification of hepatic arterial supply variants and determination of their frequency distribution in CT-angiographies. MATERIALS AND METHODS CT-angiographies of 1,568 patients were evaluated retrospectively for the period between January 1, 2010 and August 30, 2012. The hepatic arterial anatomy was assessed and categorized according to Michels's classification. So far unclassified variants were considered separately. RESULTS CT-angiographies of 1297 patients were included in the study. Type I according to Michels was seen in 937 cases (72.2 %), followed by type V in 114 patients (8.8 %) and type III in 83 patients (6.4 %). Type X could not be found in any of the patients. Not yet classified variants were discovered in 26 patients. The most frequent variant in this connection was a right hepatic artery originating from the superior mesenteric artery with the left hepatic artery originating from the left gastric artery (n = 10). CONCLUSION Michels's classification could be largely confirmed on the basis of a radiologically examined patient population. Not yet classified variants were categorized into subgroups of the existing classification. KEY POINTS Imaging of hepatic arterial supply variants using CT-angiography. Distribution of variations of arterial liver supply in a general patient population. Expansion of Michels's classification to include new variations of the arterial liver supply.