Intestinal parasitic infections (IPIs) are among the most important infectious diseases in Iran. A cross sectional study was designed to determine frequency of intestinal parasites among referrals to a large teaching hospital in Khuzestan, Southwest of Iran, 2017. A total number of 5613 stool samples were examined through direct smear and formalin-ether concentration methods to detect possible parasitic infections. Samples consisted of 2643 (47.09%) male and 2970 (52.91%) female. A total of 1468 (26.15%) samples were positive (13.11% male and 13.4% female) and 4145 (73.85%) were negative. The results also showed that 255 of samples had more than one type of parasite (mix infections). Counting single and mix parasite infections, the total number of positive cases reached to 1723. Helminthes parasites were present in 12 (0.7%) cases, while intestinal protozoan parasites were in 1711 (99.3%) cases. Almost equally, pathogenic and nonpathogenic parasites infected 860 (49.91%) and 863 (50.09%) of patients, respectively. The frequency for helminthes was determined at 0.52% with Hymenolepis nana and Enterobius vermicularis however, Giardia lamblia in 38.54% and Entamoeba histolytica/dispar at 10.68% were concluded as protozoa elements. The IPIs frequency was recorded in female and male patients at 49.16% and 50.14%, respectively. According to the current results the infection rate of intestinal parasites has been significantly reduced especially for helminths infections in this region possibly due to public attention to health issues such as; increased awareness of people, improvement of sanitation, seasonal variations, health education and personal hygiene.