The aim of the current study was to clarify the general situation of health behavior and health status of adults in rural areas of Sumbawa Prefecture, West Nusa Tenggara Province, Indonesia, and to assess the indirect influence of development assistance. The participants consisted of 200 inhabitants from two villages, with a total of 100 men and 100 women. One village, Maronge, had benefited from a development assistance project and the other, Lesen, served as the control area. A structured interview survey was carried out. The questionnaire included 61 items such as demography, economic status, health-related lifestyle, sanitary conditions, involvement of health-related community activities, health care-seeking behavior, dietary habits, and health status. Forty seven of these were analysed for the study. Adults in rural areas may have a healthy lifestyle. For example, they may exercise regularly, eat breakfast every day, and have a normal body weight. However, they might have diseases that do not appear in health statistics, such as silu. Significant differences were observed in economic status, physical exercise, smoking, dietary habit, obesity, and care-seeking behavior between the two villages. In Maronge, economic status was higher, more cigarette were smoked, and body mass index (BMI) was higher. Diabetes mellitus and hypertension were also seen. In Lesen, frequency of fish or meat intake was lower and fewer women had regular exercises habit. The current study suggests that development assistance influenced health behavior and health status through income generation.