Intramuscular fat content (marbling) is an economically important factor in many beef carcass classifi cation systems. The aim of this study was to evaluate marbling of longissimus muscle with different methods (USDA marbling score, image analysis of X-ray computed tomography scans, and conventional method), moreover it was aimed to establish the relationship between marbling traits and SEUROP conformation and fat score. Bulls (n=46) were slaughtered at an average weight of 536±126 kg and an average age of 646±437 days. The average growth rate of bulls was 955 g day -1 , the average chemical fat content of longissimus varied between 2.3 to 5.0% in fat classes. The intramuscular fat content on CT-scans closely correlated with chemical fat content (r=0.9). The highest frequency of USDA marbling score was "small" (55.2%), followed by "slight" (25.5%), "modest" (17%), and "moderate" (2.1%). Bulls with higher growth rate had lower CT-measured marbling traits in longissimus muscle (r = -0.4 --0.5). The CT scans of longissimus muscle can be used for the evaluation of marbling in Hungarian Simmental cattle. The SEUROP conformation and fat score have no relationship with marbling traits.Keywords: beef, intramuscular fat, marbling traitsAmong many beef quality traits marbling is one of the most important quality characteristics of meat demanded by consumers (PLATTER et al., 2005;MORALES et al., 2015). According to TROY and co-workers (2016), marbling not only provides higher eating quality of beef but also contains higher level of polyunsaturated fatty acids (PUFA) and monounsaturated fatty acids (MUFA) compared to other fats in beef. As a consequence, this determination and analysis of marbling plays an important role in the quality evaluation of meat. Marbling score is a component of several beef quality grading systems in the world including the United States, Japan, and Australia. It refers to visible fat found between muscle fi bre bundles within the longissimus muscle. Marbling score is assessed subjectively (visual appraisal) by a grader during the process of assigning beef quality grade. Chemical analysis is another conventional method for meat marbling evaluation, and it has been widely used as a standard method for the accurate determination of intramuscular fat content. The intramuscular fat simply quantifi es the amount (percent) of fat within the muscle, but marbling score considers amount, * To whom correspondence should be addressed. E-mail: hollo.gabriella@sic.ke.huThis is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (https://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted use, distribution, and reproduction in any medium for non-commercial purposes, provided the original author and source are credited, a link to the CC License is provided, and changes -if any -are indicated.