Background and study aim:Gastrointestinal parasites cause infectious diseases. Parasitic infection of duodenum is a relevant cause of its inflammation and appearance of upper GIT manifestation, especially in developing countries. Examination of duodenal aspirates can be very helpful in diagnosing intestinal infection because it eliminates some of the problems inherent in stool examination. The aim of this study was to estimate the prevalence of parasites in duodenal aspirate obtained by upper gastrointestinal tract endoscopy.
Subjects and methods: This cross-sectional study was conducted from March 2017 to March 2018 in sohag university hospital and Center of the digestive system. It was done on 100 patients who underwent Esophago-gastro-duodenoscopy. A total of 100 duodenal aspirate samples were collected from patients were subjected to Esophagogastroduodenoscopy for diagnostic or therapeutic reason. All cases were reviewed as regard age, sex. Cases with parasitic infestations were characterized regarding the mentioned variables. 
Results:  60 % of duodenal aspirate samples were positive. Monoparasitized patients constituted 38% (38/100) of patients while 22% were polyparasitized. There were 44 patients (44%) of Cryptosporidium infection, 21 patients (21%) of Blastocystis hominis infection, 11 patients (11%) of Cyclospora infection, 8 patients (8%) of Giardia lamblia infection.
Conclusion:  We concluded that the duodenal aspirate samples obtained during gastrointestinal endoscopic procedures helped in diagnosing the parasites.