The present study was conducted on 50 patients having cancer, in the age group from 2 months up to 80 years old, suffering from diarrhea, selected from Department of Clinical Oncology and Nuclear Medicine of Cairo University Kasr Al Ainy Hospitals for detection of Cyclospora and Isospora infections. Demographic, clinical and environmental related data were taken following included questionnaires. Cases were screened using wet mount stool examination. In addition, stool specimens were examined using the modified acid-fast staining method. Results revealed that Cyclospora was detected in 2 samples (4%), and Isospora was in 3 samples (6%) using wet mount. While, by using modified acid fast stain, there were 7 samples (14%) of Cyclospora and 3 samples (6%) of Isospora achieving substantial agreement between both tests.