History and Objectives: Since giardiasis is one of the common parasitic infestations that can lead to different personal and social problems and due to the broad spectrum of its clinical manifestation, this study was performed in order to define the prevalence of giardiasis and its clinical manifestations in 5 to 15 year-old children of Kashan in 1375.

Materials and Methods: A descriptive study was performed on 1680 children aged 5 to 15 years old of kindergarten, primary and intermediary schools by random sampling. Three stool specimens were collected from each child at three days intervals. Using formalin-ether method, the specimens were examined by a parasitologist. Demographic characteristics and clinical manifestation of the affected individuals were evaluated and recorded in the questionnaires. Then the results were statistically analyzed.

Results: 1390 children were enrolled into this study. 500 of them (36%) were infested with giardiasis. Infestation was most commonly observed in the female primary students (51.2%) and least commonly detected in the female intermediary students (6.8%). 415 (83%) of the affected individuals were symptomatic and the remainder were asymptomatic. The most common clinical manifestation was abdominal pain (70.2%) and the least common was vomiting (7.2%).

Conclusion: Considering the relatively high prevalence of this infestation, further research to find out the predisposing factors is recommended.