In the aftermath of the Great East Japan Earthquake on March 11, 2011, I received a request to serve as a sonographer in charge of lower extremity venous ultrasound screening as part of the “economy-class syndrome medical care group,” popularly referred to as “team Eco,” which was organized by Fukushima Medical University. I visited refugees at various locations in Fukushima Prefecture and carried out lower extremity venous ultrasound checks for one week beginning on April 4. I had various valuable experiences including preparation of a pocket guide and setting up hands on classes about securing lower extremity venous ultrasound check workers, procuring ultrasound units, dispatching information about our activities, and future activities. A natural disaster can happen anywhere at any time. Medical institutions, scientific organizations, the government, and other groups should work together to set up a system that is capable of responding rapidly and smoothly in the event of a natural disaster.