A community based cross sectional survey was done in Gambella special wereda to determine thernhousehold illness prevalence and its determinants among under five children. A total of 831 childrenrnwere included in the study. The household illness prevalence was 50.6%. The most common types ofrnillnesses were diarrhea (20.5%), malaria (17.8%), cough/shortness of breath (6.7%), fever (6.6%),rnmeasles (0.5%) and other illnesses (7.2%).rnWith regard to malnutrition, the prevalence of stunting was 37.3% wasting, 26.4%, underweightrn29.2% and mid upper arm circumference less or equal to 13.5 centimeters was 26.0%.rnThe factors associated with household illness were area of residence, income, stunting, underweight,rntime of initiation of breastfeeding, bed net in household, immunization for measles, uvulectomy,rnmilk teeth extraction, and pre lacteal feeding (p