Diarrhea is considered a global health problem and a major mortality cause in children less than 5 years of age. Infectious diarrhea is usually associated with morbidity in the form of intestinal dysfunction and malnutrition. One of the major causes of diarrhea is intestinal parasitic infections. In this study, we investigate the parasitic causes of diarrhea in patients visiting King Abdulaziz University Hospital (KAUH) in Jeddah, Saudi Arabia during 2014. A total of 627 stool samples was received during 2014 at the Parasitology lab for stool analysis. Samples were analyzed using the formalin-ethyl acetate concentration technique and a direct smear was performed for all diarrheic samples. A thick smear was prepared from all diarrheic specimens and permanently stained with a modified Ziehl-Neelsen staining procedure to look for the presence of Cryptosporidium. Four hundred and eighty (76.6%) specimens were negative for intestinal parasites and 88 (14%) non-diarrheic specimens were positive for intestinal parasites. Fifty-nine (9.4%) specimens were diarrheic and 30 of them had intestinal parasites. The most frequent parasites seen in diarrheic samples were Giardia lamblia (28.8%) and Entamoeba histolytica (10.2%). Cryptosporidium was found in only 2 (3.4%) diarrheic specimens. The Results of this work recommend the establishment of a high standard sewage system to provide a better quality of life