Intestinal parasitic infection is one of the major public health problems in developing countries. Children are more vulnerable to these infections. In addition, the prevalence of infection is different among various communities; hence, there is a need for the periodical prevalence evaluation. This study was performed to define the prevalence of intestinal parasitic infection among the students of South Khorasan Province, eastern Iran in 2007.A cross-sectional study was performed on 2169 students aged 6-11 years in six cities of South Khorasan Province in 2007. Three stool specimens were collected from each student. Specimens were examined with direct wet and formalin ethyl acetate method. Data were analyzed with SPSS version 15 software.From a total 2169 students, 47.7% were infected with one or more intestinal parasites. Almost 33.4% were pathogen parasites. The most common parasite was Giardia (28.7%). The prevalence rate of infection was significantly higher in rural area than that of urban area (P=0.001). The prevalence of infection was also much more common in those students whose parents were less educated.Prevalence of intestinal parasitic infection in this region is remarkable. Public health education and using healthy water are recommended.