From April 2016 to the end of July 2024, roadkill mammals were recorded using the road sampling method on the 33.4 km-long Zmajevac-Osijek road in Osijek-Baranja County, located in the northeastern part of Croatia. A total of 86 roadkill specimens of wild mammals, classified into eight species and one subspecies, were recorded. The northern white-breasted hedgehog, Erinaceus roumanicus, topped the list with 38 individuals, followed by the European badger, Meles meles, with 23 individuals, and the red fox, Vulpes vulpes, with 13 individuals. The European badger was the most frequent roadkill in February and March. The northern white-breasted hedgehog was the most common roadkill in June and July, while the red fox was most frequent roadkill in October. The average number of roadkill per km on the Zmajevac-Osijek road, divided into nine road sections, ranged from 1.1 to 5.9. Spearman’s correlation coefficient between the length of the section and the number of roadkill mammals showed a moderate correlation. The only strong positive correlation between roadkill wild mammals and traffic (average annual daily traffic or average summer daily traffic) was recorded for State Road D-212.