Cryptosporidiosis, the disease caused by protozoa of the genus Cryptosporidium, represents a major public health problem in both developing and developed countries. The infection can be severe and life threatening among immunocompromised individuals, particularly in AIDS patients and in those with primary immunodeficiency diseases. This review examines the essential aspects of the epidemiology of the infection, highlighting the role of animals, water and food. A critical evaluation of the diagnostic tools used in clinical settings is also provided. Lastly, the review examines the chemotherapeutic options available to treat the infection, and underlines the need to design and test new drugs. The review concludes with a five-year outlook on some aspects of interest for future research on this pathogen.