Cyclospora spp. which are coccidian parasites are rare gastroenteritis pathogens. The first cyclosporiasis case in Turkey was reported in 1998 in a patient with AIDS. In this paper we report a case of Cyclospora gastroenteritis, in a patient who was admitted to our hospital and who had had diarrhea, abdominal pain and nausea for ten days. In the anamnesis it was learned that he had travelled to the Black Sea region and had drunk muddy and cloudy water. His physical examination was normal except for increased bowel sounds. There were no leukocytes or erythrocytes in the direct microscopy of the stool and bacteriologic culture did not yield any enteropathogen. Cylospora oocyysts were seen in the parasitologic exmination. The patient was treated with cotrimaxasole (2x1,160/800 mg tablet). There was no pathogen in the repeated stool examination. Our case suggests that parasitologic examination should not be neglected in longlasting diarrhea cases and occasionally Cyclospora may be the causative agent.