Purpose of Review: The present review focuses on recent epidemiological and diagnostic advances in cystoisosporiasis and cyclosporiasis. Recent Findings: Continuous outbreaks of these parasites occur worldwide. Sporadic cases in the United States are travel acquired, but also domestically acquired. New molecular diagnostic methods allow for accurate early diagnosis in humans, and might potentially decrease the burden of disease by detecting these parasites in vehicles of transmission. Summary: Better understanding of the epidemiology of Cyclospora cayetanensis and to a less extent to Cystoisospora belli has been gained recently. However, several gaps still remain in knowledge on the transmission and on mechanisms of persistent infection in immunosuppressed patients and prevention. New molecular methods might help in filling these gaps and in controlling transmission. © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins.