Background: Malaria is a contagious disease of global concern. It is still a public health problem as it often causes extraordinary events (ECOs) that have a broad impact on the quality of life and the economy and can lead to death. Aim. The Aim of this research is to analyze the relationship of risk factors of home and environmental conditions with the history of malaria incidents and prevention efforts in the village of Watupuda and Patawang village of Melolo district of East Sumba province of East Nusa Tenggara. Method.This type of study is a quantitative descriptive study with a case control approach or a retrospective study, a control group sample is validated based on the number of case samples of 48, a 1:1 comparison with a total of 96 respondents.Result. The results of bivariate analysis of the environment in the house show that the type of wall is a risk factor (OR = 2.235) house ventilation is a risk factor (OR = 3.262), house windows are a risk factor (OR = 4.175), occupancy density is a risk factor (OR = 4.414) and environmental factors Outside the house shows the presence of livestock is a risk factor (OR = 5, 057) and which is not a risk factor is the distance of the house with stagnant water (OR = 0.507) and behavioral factors show the habit of going out at night is a risk factor (OR = 6.854), the use of mosquito nets is a risk factor (OR = 4.892), the use of antimosquito drugs is a risk factor (OR = 7.457), the habit of hanging pakayan is a risk factor (OR = 4.287). Multivariate analysis showed that the habit of leaving the house at night was the most influential risk factor for malaria incidence with an OR = 6.854 and CI (95%)=(7.606¬-11.393).Conclusion. The type of wall, house ventilation, house windows, density of house occupants and the presence of animals, the habit of going out at night, the use of mosquito nets, the use of anti-mosquito drugs, the habit of hanging clothes are risk factors where the OR value> 1 and the habit of going out at night which is the most influential risk factor for the incidence of malaria and the distance between the house and puddles is not a risk factor for the external environment that affects the occurrence of malaria.