Background: Intestinal parasitic infestations are one of the neglected tropical diseases and it is the most common among school children. It negatively affects children’s growth, cognitive development and learning abilities. It may lead to nutritional deficiencies and anemia. Objective: to identify the effect of parasitic infestations on the school achievements among primary school children. Methods: Descriptive comparative design was conducted on a sample of 200 children (100 infected study group, and 100 not infected) at Hehia primary schools, Sharkia Governorate, Egypt. Two tools were used; A questionnaire interview sheet and A student performance assessment form. Results: 65% of infected children were males particularly in families with a large size (their crowding index was >1.5). School children of unemployed parents and/or parents with a low educational level were at higher risk of contracting parasitic infections. There was a statistically significant difference between both the infected and non-infected groups concerning the educational achievement domains. Conclusion: All of the studied parasitic infected children had lower school achievements.