Hanoi zoo is a place to display animal species serving the people and foreigners to visit, play and entertain. At the same time, the zoo is also a place for scientific research into animals, contributing to the preservation and education of the preservation of the natural environment. The zoo has been constantly upgraded and renovated to meet the needs of entertainment, education for people both of the capital and the country. With the number of millions of visitors every year, it is said that the park is attractive and effective. The purpose of this study was to investigate the parasite infection in the monkeys at Hanoi zoo and integrate these results for biological teaching in secondary school students in Hanoi. 48 fresh fecal samples were collected from six primate species and examined using Willis method, as a standard parasitological technique. There were 28 samples infected with parasites, accounting for 58.3%. The prevalence of parasitic infections in adult females (67.9%) was higher than that of adult males (44.4%). Results showed that there were three genera of parasites such as Trichuris, Strongyloides and Entamoeba. The hookworm was found only in Macaca fascicularis and mild infection. Six study species were infected by Entamoeba protozoa. It could be concluded that, there was gastrointestinal parasite infection among six species of Cercopithecidae family examined in Hanoi zoo. With the research results obtained, we integrated into biological teaching for some secondary school students in Hanoi to raise awareness of environmental protection at Hanoi zoo as recommended some solutions for visitors.