The aim of the study was to evaluate the bacterial contamination of beef carcass surfaces in relation to the order of slaughtering cattle during a slaughter day. The research was conducted on carcasses from a slaughterhouse approved to produce for the market. The daily average number of cattle slaughtered in the facility was 237. For the purpose of determining the total count of aerobic bacteria, bacteria from the Enterobacteriaceae family and Enterococci, 40 carcasses were examined (8 per each working day), whereas 50 carcasses (10 per each working day) were used to detect the presence of Salmonella rods. The microbiological denotation of particular bacterial groups was conducted according to the relevant Polish Standards. Samples for examination were collected by the destructive technique and swabbing (with sterile swabs) from the rump, neck, plate and chuck of carcasses before chilling, in accordance with the Polish Standards. It was found that the order of slaughtering cattle during a slaughter day had no significant influence on the total bacterial count on the examined carcass surfaces. The total count of aerobic bacteria in beef carcasses ranged from 1.8 × 10² cfu/cm² (2.26 log cfu/cm²), at the first stage of the slaughter process, to 5.9 × 10² cfu/cm² (2.77 log cfu/cm²), at the third stage of the slaughter process. In most cases no relationship was observed between the total bacterial count and the day of the week on which the examination took place. The daily log mean value of contamination fell within the range of 3.5 × 10² (2.55 log cfu/cm²) to 8.3 × 10² cfu/cm² (2.92 log cfu/cm²). Only on the third working day the total aerobic count was found to be significantly lower (8.7 × 10¹ cfu/cm² - 1.94 log cfu/cm²) than on the fourth day. The values determined were lower than the hygienic standards for the slaughter process set in Commission Regulation (EC) No. 2073/2005 by about 1 to 0.4 log (and as much as 1.4 log on the third working day), respectively. The bacteria from the Enterobacteriacae family were found in 23% of samples examined and Enterococci in 45%. Contamination with the above bacteria was insignificant as it did not exceed 8 cfu/cm² for Enterobacteriacae and 3.2 × 10¹ cfu/cm² for Enterococci. None of the samples examined was found to be contaminated with Salmonella rods. Neither the order of slaughtering cattle during a slaughter day nor the day of the week on which the examination took place affected the total bacterial contamination of carcasses. The standard of sanitary supervision in the slaughterhouse was good.