Ecological and social fators play very important roles in the control of emerging infectious diseases, beside case management, surveillance and laboratory examinations. The ecological factors include physical environmental factors such as altitude, latitude, climate, season, temperature, humidity, water, air, food and land; as well as biological environmental factors such as flora, fauna, agent, vector, host and biological agents used for vector control. The social factors include: education, economic status, behaviour, attitude, habit, religion, culture, population migration and density. Intervention to ecological and social factors could be done as preventive measures. We should learn from the failures as well as successes in the control of infectious diseases which gave considerations on ecological and social factors. For new diseases, studies should also be conducted to know what kinds of ecological and social factors have important roles in the control of these diseases.