Infection caused by intestinal parasites has significant public health consequences amongst children in the developing world. Street children are an under-studied group of society subjected to increased health risks when compared to their peers. To estimate the prevalence of intestinal parasitic infection and ascertain risk factors for parasitosis amongst this population, stool samples were collected from 258 children across four orphanages in three districts of Lima, Peru. Surveys were used to determine associations between risk factors and infection status. The prevalence of parasitic infection within the study sample was 66·3%, with 30·6% testing positive for pathogenic species. Entamoeba coli was the most commonly detected parasite (41·9%) and Giardia lamblia was the most commonly detected pathogenic parasite (17·1%). Of the group 15·1% had helminth infection. When testing for association, age and BMI were risk factors for infection. A notable difference in prevalence (P < 0·00001) based on orphanage was observed, but the duration of residence in an orphanage was not a predictor for infection. A sub-analysis conducted amongst children who were given anti-parasitic treatment 5 months beforehand found no significant difference in parasitosis between those who had been given treatment and those who had not (P  =  0·218). It is suggested that a single dose of albendazole alone may not be effective in combating long-term infection rates.