This study reports on detection and prevalence of intestinal parasites among school children in Port Harcourt, the capital city of Rivers State, Nigeria. Stool samples were collected from 100(46.5%) males and 115(53.5%) females. Microscopic examination of both thin and thick films of the stool sample were done. In all, three intestinal helminthes were identified. The overall prevalence was 30.7% and this was predominantly among male school children (37.0%) than in females (25.2%) from both locations. Of the three parasite species observed, T. trichiura (39.4%) was the most predominant helminthes in this study. This was closely followed by A. lumbricoides (33.3%) and hook worm (27.3%) was the least. Generally, intestinal helminthes was most predominant in samples from Emohua State Primary School (ESPS), Emohua (90.9%) than those from University Demonstration Primary School (UDPS) in Choba (9.1%)]. Intestinal helminthes were most predominant among children aged 10-15 years (57.6%) than those within age group 5-9 years (42.4%) of age from both locations. It further showed that among the male school children, A. lumbricoides (63.6%) was most predominant, followed by hook worms (55.6%) and T. trichiura (50.0%) was least predominant. There were no incidence or prevalence of multiple infections of any of the three helminthes in the study. This study shows that a good percentage of people were infested by parasitic protozoa and worms and reinforces the need for an urgent effort to check the unnecessary and avoidable heavy parasites load. [Odu NN, Okonko IO, and Erhi O. Study of Neglected tropical diseases (NTDs): Gastro-Intestinal Helminthes among school children in Port Harcourt, Rivers State. Report and Opinion 2011;3(9):6-16]. (ISSN: 1553-9873). http://www.sciencepub.net.