The aim of this study was to describe epidemiologic characteristics of intestinal parasites in a population in south of Tehran, Iran. A retrospective cross-sectional study of patients with suspicious intestinal parasitic infections referred to the Zakaria Razi Laboratory in Shahre-Ray, southern Tehran, Iran, was conducted from April 21, 2004 to October 20, 2005. All stool samples were examined and socio-demographic informations were retrieved. Of 4,371 referred patients, 466 (239 males and 227 females) were laboratory diagnosed with intestinal parasites, with a period prevalence of 10.7%. Blastocystis hominis (B. hominis) and Giardia lamblia (G. lamblia) were the most frequent intestinal parasites. More than half of patients aged (3) 18 years had a low level of educational attainment (e.g. illiterate, primary school, high school) (170/331, 54.1%). Further, majority of patients were homemakers (42.3%, 140/331) or workers (28.1%, 93/331) employed in various business settings such as food industry and construction. Findings of this study showed that intestinal parasitic infections are still a major public health challenge in Iran that needs to be addressed. We believe that public education, improving sanitation conditions of underdeveloped areas/communities, community involvement, and supporting evidence-based practice/programs are the major keys to success in preventing the spread of intestinal parasitic infections in Iran.