The field survey has been performed to study the epidemiology of calf coccidiosis in Poland. It was found that the Eimeria spp. coccidia occurred on 93.0 % of the investigated farms. But the highly pathogenic species (E. bovis and E. zuernii) were found on 88.4 % of the investigated farms. Those were also found more frequently in bigger farms (92.3%) compared to smaller ones (85.1%). However, the intensity of E. bovis as well as E. zuernii infection remained, in most cases, low – 75.4 and 79.8% or moderate – 21.3 and 18.5%, respectively. The intensity of those infections was, respectively, 3.1x and 1.9x higher in big farms. Conclusion: The Eimeria spp. are very common pathogens in cattle farms in Poland. The highly pathogenic Eimeria occurred more frequently in big rather than in small farms.