Six patients infected with Cyclospora cayetanensis who sought medical care at three different hospitals in Turkey are herein presented. Four patients were male and the others were female and their ages ranged from 7 to 62 years. The first patient was HIV-positive and presented with watery diarrhea with a frequency of up to 18 times a day for more than ten months and diagnosed as cyclosporiosis in Kayseri, 1996. The second patient was also HIV positive and diagnosed as cyclosporiosis in Kayseri, 2000. The third patient was an acute myeloblastic leukemia (AML) patient and diagnosed in Istanbul, 2000. The fourth patient was idiopathic hepatic cirrhosis complaining of diarrhea and weakness and diagnosed in Kayseri, 2001. The fifth and sixth patients were immunocompetent patients complaining of diarrhea and diagnosed in Izmir and Kayseri, 2002. Diarrhea occurring from one to ten times a day continued for 7 to 70 d in the last 5 patients. Treatment with a trimethoprim/sulfamethoxazole compound was done for all patients. Both symptomatic and parasitologic improvements were quickly observed. In summary, C. cayetanensis infection is rare in Turkey and most patients infected with this pathogen tend to be immunosuppressive individuals at present.