Cryptosporidium parvum is a zoonotic protozoan parasite occurring in a wide range of hosts. Invasions caused by this parasite have been reported in humans and in many animal species including birds. Despite its worldwide prevalence, infections have usually generated considerable losses in the livestock industry, mostly affecting calves, lambs and goat kids. It has previously been shown that ruminants are a major reservoir of zoonotic Cryptosporidium parvum and contact with an infected animal can lead to human infection. The application of molecular methods for parasitological diagnostics has increased our knowledge on the parasite hosts and its prevalence in humans and animals. They also confirmed their usefulness during epidemiological investigations and in surveillance studies of human and animal cryptosporidiosis. In this review the current state of knowledge concerning the importance of Cryptosporidium parvum invasions in farm and wild animals was presented.