An epizootiological field study on tick-borne protozoan infections in foxes (Vulpes vulpes) was carried out in different parts of Croatia. Spleen samples of 191 carcasses of red foxes killed in sanitary hunting, were examined for the presence of hematozoa by polymerase chain reaction (PCR) and subsequent sequencing. The investigation revealed four species of hematozoa in 57 foxes (30%), namely Theileria annae, Theileria sp. 3182/05 and Hepatozoon canis. T. annae was found in 10 foxes (5%), Theileria sp. 3182/05 in a single animal (1%), H. canis in 44 (23%) and Hepatozoon sp. was detected in two foxes (1%). T. annae and H. canis were distributed through all the studied regions, while Theileria sp. 3182/05 and Hepatozoon sp. were restricted to the Zagreb and Zagorje, and Istria regions, respectively. Detection of T. annae in all regions of Croatia indicates the presence of the natural cycle of the parasite and raises the possibility of other vectors other than the proposed Ixodes hexagonus.