Chronic diarrhea is one of the major AIDS-defining illnesses in WHO Classification and occurs in 60-90% of HIV-infected patients in Africa. We did a case series study on parasite isolation in stool samples of AIDS patients with chronic diarrhea using wet-mount, Formol-Ether concentration technique and Modified Acid-Fast staining method in Gondar Teaching Hospital between January and September 2000. Seventy AIDS patients with chronic diarrhea were included in the study. Wasting syndrome was the clinical presentation in (97%) almost all AIDS patients who had chronic diarrhea. Intestinal parasites were detected in 41 out of 70 diarrheal specimens in AIDS patients. Multiple parasitic injections were detected in three diarrheal specimens. Intracellular parasite, (29%) Cryptosporidium parvum, and mucosal parasite, (17%) Strongyloides stercoralis were the frequently isolated parasites in diarrheal specimens of AIDS patients, accounting for 80% diarrhaegen pathogens among positive specimens. Cryptosporidium parvum, under-estimated cause of chronic diarrhea in immunocompetent adults, was found to be the prominent diarrheagen in AIDS patients in this study, similar with other studies in different African countries.