This study was undertaken in order to characterize a Cryptosporidium muris-like parasite isolated from cattle in Hungary and to compare this strain with other Cryptosporidium species. To date, the large-type oocysts isolated from cattle were considered as C. muris described from several mammals. The size, form, and structure of the oocysts of the Hungarian strain were identical with those described by others from cattle. An apparent difference between the morphometric data of C. muris-like parasites isolated from cattle or other mammals was noted, which is similar in magnitude to the differences between Cryptosporidium meleagridis and Cryptosporidium felis or between Cryptosporidium serpentis and Cryptosporidium baileyi. The cross-transmission experiments confirmed the findings of others, as C. muris-like oocysts isolated from cattle fail to infect other mammals. The sequence of the variable region of small subunit (SSU) rRNA gene of the strain was 100% identical with that of the U.S. Cryptosporidium andersoni and C. andersoni-like isolates from cattle. The difference between the SSU rRNA sequence of bovine strains and C. muris is similar in magnitude to the differences between C. meleagridis and Cryptosporidium parvum anthroponotic genotype or between Cryptosporidium wrairi and C. parvum zoonotic genotype. Our findings confirm that the Cryptosporidium species responsible for abomasal cryptosporidiosis and economic losses in the cattle industry should be considered a distinct species, C. andersoni Lindsay, Upton, Owens, Morgan, Mead, and Blagburn, 2000.