Objective:To provide baseline information of parasitic infections in 3 suburban govment schools, Lakhok subdistrict of Muang Pathum Thani, Thailand. Methods: This study was conducted between May-June 2010 using simple direct smear and modified formalin ether and from a population of 1 253 in 3 suburban govment schools. Results: Total samples of 202 registered and participated. The average of prevalence of infection from 3 schools was 13.9%, there were 13.7%, 14.3%and 13.9%in N, S and R school, respectively with no significant difference between schools (P>0.05). The infection rates did not show significant difference between genders (P>0.05). The highest rate of infection was 20.4%in Pathom 2 (8 years) students and the lowest was 4%in Pathom 1 (7 years) with statistically difference between age groups (P<0.05). The highest prevalence of pathogenic protozoa was Giardia lamblia (G. lamblia) which was found in 50%of infected cases, followed by 25%of Entamoeba histolytica (E. histolytica) and Blastocystis hominis (B. hominis). The highest prevalence of non-pathogenic protozoa was Endolimax nana (E. nana) which was found in 88.9%, followed by 11.1%of Entamoeba coli (E. coli). Mixed infections between Blastocystis hominis (B. hominis) and Endolimax nana (E. nana) were reported at 7.1%. The only helminthic infection found in this study area was hookworm, found in 1 student (3.8%). The formalin ether concentration technique showed a higher efficacy of detection (78%-100%) than the simple direct smear method (0%-50%). Conclusions: Surveillance of Protozoan infections may need to be focused on suburban areas.