ABSTRACT This article aimed to analyze the occurrence of acute diarrhea in children under five years old assisted by the Family Health Strategy of Guaratiba Island, and housing and sanitation conditions of the locality. A cross-sectional epidemiological study was carried out. The analysis of the variables was made by using simple and multiple logistic regression. The variables that showed association with diarrhea were: (a) children <2,5 years old; attend daycare/school and family income