This chapter focuses on the impact of tropical cyclones on human societies. This includes public health; the mortality and morbidity resulting from these events; intervention measures such as evacuation; medical preparedness for the affected population; and mitigation, prevention, and response strategies for the medical community drawn from a global perspective. Recent large cyclonic storms such as Hurricanes Katrina and Rita in the U.S. and Typhoon Nari that caused devastation in Taiwan reaffirmed the need to meet the complex challenge of public health planning, especially for those with special needs. Typically, hospitals experience a lull in emergency department visits around the time the tropical cyclone makes landfall and in the storm's immediate aftermath. Part of disaster planning is deciding which medical supplies should be stockpiled for a tropical cyclone and its aftermath. Supplies of tetanus toxoid, oral and parental antibiotics, hypoglycemics, and others are needed in the aftermath of a cyclone.