Worm infestation is mainly caused by soil-transmitted helminths (STH) infecting one-third of the world’s population, where the most affected are primary school children. This chronic, long-lasting infection can affect the growth aspects in children. A school-based deworming is one of the treatments recommended by WHO to counterattack worm infection in primary school children. To evaluate the effect of school-based deworming on the hemoglobin level, growth and school performance of primary school children, an open randomized clinical trial was conducted on 165 targeted populations in SukaKaro village, North Sumatra; 156 of which were then chosen based on inclusion and exclusion criteria. The samples’ feces- sampling, hemoglobin level, and growth chart data were recorded on the first day of study before any treatment was given. They were then divided into two groups; the first group of 80 samples did not receive any treatment, while the second group of 76 samples received 400mg of albendazole as part of a school-based deworming program. The samples were being followed up after sixth months of study. In conclusion, albendazole is able to improve the hemoglobin level, growth development, and school performance of the samples, although there were no significant differences between the two groups.